config_file.c 40.5 KB
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/*
Edward Thomson committed
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 * Copyright (C) the libgit2 contributors. All rights reserved.
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 *
Vicent Marti committed
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 * This file is part of libgit2, distributed under the GNU GPL v2 with
 * a Linking Exception. For full terms see the included COPYING file.
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 */

#include "common.h"
#include "config.h"
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#include "filebuf.h"
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#include "sysdir.h"
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#include "buffer.h"
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#include "buf_text.h"
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#include "git2/config.h"
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#include "git2/sys/config.h"
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#include "git2/types.h"
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#include "strmap.h"
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#include "array.h"
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#include <ctype.h>
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#include <sys/types.h>
#include <regex.h>
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GIT__USE_STRMAP;
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typedef struct cvar_t {
	struct cvar_t *next;
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	git_config_entry *entry;
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	bool included; /* whether this is part of [include] */
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} cvar_t;
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typedef struct git_config_file_iter {
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	git_config_iterator parent;
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	git_strmap_iter iter;
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	cvar_t* next_var;
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} git_config_file_iter;

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/* Max depth for [include] directives */
#define MAX_INCLUDE_DEPTH 10
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#define CVAR_LIST_HEAD(list) ((list)->head)

#define CVAR_LIST_TAIL(list) ((list)->tail)

#define CVAR_LIST_NEXT(var) ((var)->next)

#define CVAR_LIST_EMPTY(list) ((list)->head == NULL)

#define CVAR_LIST_APPEND(list, var) do {\
	if (CVAR_LIST_EMPTY(list)) {\
		CVAR_LIST_HEAD(list) = CVAR_LIST_TAIL(list) = var;\
	} else {\
		CVAR_LIST_NEXT(CVAR_LIST_TAIL(list)) = var;\
		CVAR_LIST_TAIL(list) = var;\
	}\
} while(0)

#define CVAR_LIST_REMOVE_HEAD(list) do {\
	CVAR_LIST_HEAD(list) = CVAR_LIST_NEXT(CVAR_LIST_HEAD(list));\
} while(0)

#define CVAR_LIST_REMOVE_AFTER(var) do {\
	CVAR_LIST_NEXT(var) = CVAR_LIST_NEXT(CVAR_LIST_NEXT(var));\
} while(0)

#define CVAR_LIST_FOREACH(list, iter)\
	for ((iter) = CVAR_LIST_HEAD(list);\
		 (iter) != NULL;\
		 (iter) = CVAR_LIST_NEXT(iter))

/*
 * Inspired by the FreeBSD functions
 */
#define CVAR_LIST_FOREACH_SAFE(start, iter, tmp)\
	for ((iter) = CVAR_LIST_HEAD(vars);\
		 (iter) && (((tmp) = CVAR_LIST_NEXT(iter) || 1));\
		 (iter) = (tmp))

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struct reader {
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	time_t file_mtime;
	size_t file_size;
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	char *file_path;
	git_buf buffer;
	char *read_ptr;
	int line_number;
	int eof;
};

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typedef struct {
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	git_atomic refcount;
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	git_strmap *values;
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} refcounted_strmap;

typedef struct {
	git_config_backend parent;
	/* mutex to coordinate accessing the values */
	git_mutex values_mutex;
	refcounted_strmap *values;
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	int readonly;
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} diskfile_header;

typedef struct {
	diskfile_header header;

	git_config_level_t level;
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	git_array_t(struct reader) readers;
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	char  *file_path;
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} diskfile_backend;
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typedef struct {
	diskfile_header header;

	diskfile_backend *snapshot_from;
} diskfile_readonly_backend;

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static int config_parse(git_strmap *values, diskfile_backend *cfg_file, struct reader *reader, git_config_level_t level, int depth);
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static int parse_variable(struct reader *reader, char **var_name, char **var_value);
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static int config_write(diskfile_backend *cfg, const char *key, const regex_t *preg, const char *value);
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static char *escape_value(const char *ptr);
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int git_config_file__snapshot(git_config_backend **out, diskfile_backend *in);
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static int config_snapshot(git_config_backend **out, git_config_backend *in);
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static void set_parse_error(struct reader *reader, int col, const char *error_str)
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{
	giterr_set(GITERR_CONFIG, "Failed to parse config file: %s (in %s:%d, column %d)",
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		error_str, reader->file_path, reader->line_number, col);
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}

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static int config_error_readonly(void)
{
	giterr_set(GITERR_CONFIG, "this backend is read-only");
	return -1;
}

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static void cvar_free(cvar_t *var)
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{
	if (var == NULL)
		return;

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	git__free((char*)var->entry->name);
	git__free((char *)var->entry->value);
	git__free(var->entry);
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	git__free(var);
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}

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int git_config_file_normalize_section(char *start, char *end)
{
	char *scan;

	if (start == end)
		return GIT_EINVALIDSPEC;

	/* Validate and downcase range */
	for (scan = start; *scan; ++scan) {
		if (end && scan >= end)
			break;
		if (isalnum(*scan))
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			*scan = (char)tolower(*scan);
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		else if (*scan != '-' || scan == start)
			return GIT_EINVALIDSPEC;
	}

	if (scan == start)
		return GIT_EINVALIDSPEC;

	return 0;
}

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/* Add or append the new config option */
static int append_entry(git_strmap *values, cvar_t *var)
{
	git_strmap_iter pos;
	cvar_t *existing;
	int error = 0;

	pos = git_strmap_lookup_index(values, var->entry->name);
	if (!git_strmap_valid_index(values, pos)) {
		git_strmap_insert(values, var->entry->name, var, error);
	} else {
		existing = git_strmap_value_at(values, pos);
		while (existing->next != NULL) {
			existing = existing->next;
		}
		existing->next = var;
	}

	if (error > 0)
		error = 0;

	return error;
}

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static void free_vars(git_strmap *values)
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{
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	cvar_t *var = NULL;
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	if (values == NULL)
		return;
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	git_strmap_foreach_value(values, var,
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		while (var != NULL) {
			cvar_t *next = CVAR_LIST_NEXT(var);
			cvar_free(var);
			var = next;
		});
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	git_strmap_free(values);
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}

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static void refcounted_strmap_free(refcounted_strmap *map)
{
	if (!map)
		return;

	if (git_atomic_dec(&map->refcount) != 0)
		return;

	free_vars(map->values);
	git__free(map);
}

/**
 * Take the current values map from the backend and increase its
 * refcount. This is its own function to make sure we use the mutex to
 * avoid the map pointer from changing under us.
 */
static refcounted_strmap *refcounted_strmap_take(diskfile_header *h)
{
	refcounted_strmap *map;

	git_mutex_lock(&h->values_mutex);

	map = h->values;
	git_atomic_inc(&map->refcount);

	git_mutex_unlock(&h->values_mutex);

	return map;
}

static int refcounted_strmap_alloc(refcounted_strmap **out)
{
	refcounted_strmap *map;
	int error;

	map = git__calloc(1, sizeof(refcounted_strmap));
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	GITERR_CHECK_ALLOC(map);
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	git_atomic_set(&map->refcount, 1);
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	if ((error = git_strmap_alloc(&map->values)) < 0)
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		git__free(map);
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	else
		*out = map;
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	return error;
}

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static int config_open(git_config_backend *cfg, git_config_level_t level)
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{
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	int res;
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	struct reader *reader;
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	diskfile_backend *b = (diskfile_backend *)cfg;
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	b->level = level;

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	if ((res = refcounted_strmap_alloc(&b->header.values)) < 0)
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		return res;
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	git_array_init(b->readers);
	reader = git_array_alloc(b->readers);
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	if (!reader) {
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		refcounted_strmap_free(b->header.values);
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		return -1;
	}
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	memset(reader, 0, sizeof(struct reader));

	reader->file_path = git__strdup(b->file_path);
	GITERR_CHECK_ALLOC(reader->file_path);

	git_buf_init(&reader->buffer, 0);
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	res = git_futils_readbuffer_updated(
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		&reader->buffer, b->file_path, &reader->file_mtime, &reader->file_size, NULL);
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	/* It's fine if the file doesn't exist */
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	if (res == GIT_ENOTFOUND)
		return 0;

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	if (res < 0 || (res = config_parse(b->header.values->values, b, reader, level, 0)) < 0) {
		refcounted_strmap_free(b->header.values);
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		b->header.values = NULL;
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	}
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	reader = git_array_get(b->readers, 0);
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	git_buf_free(&reader->buffer);
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	return res;
}

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/* The meat of the refresh, as we want to use it in different places */
static int config__refresh(git_config_backend *cfg)
{
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	refcounted_strmap *values = NULL, *tmp;
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	diskfile_backend *b = (diskfile_backend *)cfg;
	struct reader *reader = NULL;
	int error = 0;

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	if ((error = refcounted_strmap_alloc(&values)) < 0)
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		goto out;

	reader = git_array_get(b->readers, git_array_size(b->readers) - 1);
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	GITERR_CHECK_ALLOC(reader);
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	if ((error = config_parse(values->values, b, reader, b->level, 0)) < 0)
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		goto out;

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	git_mutex_lock(&b->header.values_mutex);

	tmp = b->header.values;
	b->header.values = values;
	values = tmp;

	git_mutex_unlock(&b->header.values_mutex);
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out:
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	refcounted_strmap_free(values);
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	if (reader)
		git_buf_free(&reader->buffer);
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	return error;
}

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static int config_refresh(git_config_backend *cfg)
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{
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	int error = 0, updated = 0, any_updated = 0;
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	diskfile_backend *b = (diskfile_backend *)cfg;
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	struct reader *reader = NULL;
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	uint32_t i;
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	for (i = 0; i < git_array_size(b->readers); i++) {
		reader = git_array_get(b->readers, i);
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		error = git_futils_readbuffer_updated(
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			&reader->buffer, reader->file_path,
			&reader->file_mtime, &reader->file_size, &updated);
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		if (error < 0 && error != GIT_ENOTFOUND)
			return error;
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		if (updated)
			any_updated = 1;
	}

	if (!any_updated)
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		return (error == GIT_ENOTFOUND) ? 0 : error;
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	return config__refresh(cfg);
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}

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static void backend_free(git_config_backend *_backend)
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{
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	diskfile_backend *backend = (diskfile_backend *)_backend;
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	uint32_t i;
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	if (backend == NULL)
		return;

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	for (i = 0; i < git_array_size(backend->readers); i++) {
		struct reader *r = git_array_get(backend->readers, i);
		git__free(r->file_path);
	}
	git_array_clear(backend->readers);

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	git__free(backend->file_path);
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	refcounted_strmap_free(backend->header.values);
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	git_mutex_free(&backend->header.values_mutex);
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	git__free(backend);
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}

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static void config_iterator_free(
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	git_config_iterator* iter)
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{
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	iter->backend->free(iter->backend);
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	git__free(iter);
}
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static int config_iterator_next(
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	git_config_entry **entry,
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	git_config_iterator *iter)
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{
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	git_config_file_iter *it = (git_config_file_iter *) iter;
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	diskfile_header *h = (diskfile_header *) it->parent.backend;
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	git_strmap *values = h->values->values;
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	int err = 0;
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	cvar_t * var;
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	if (it->next_var == NULL) {
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		err = git_strmap_next((void**) &var, &(it->iter), values);
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	} else {
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		var = it->next_var;
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	}
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	if (err < 0) {
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		it->next_var = NULL;
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		return err;
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	}
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	*entry = var->entry;
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	it->next_var = CVAR_LIST_NEXT(var);
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	return 0;
}
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static int config_iterator_new(
	git_config_iterator **iter,
	struct git_config_backend* backend)
{
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	diskfile_header *h;
	git_config_file_iter *it;
	git_config_backend *snapshot;
	diskfile_backend *b = (diskfile_backend *) backend;
	int error;
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	if ((error = config_snapshot(&snapshot, backend)) < 0)
		return error;

	if ((error = snapshot->open(snapshot, b->level)) < 0)
		return error;

	it = git__calloc(1, sizeof(git_config_file_iter));
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	GITERR_CHECK_ALLOC(it);

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	h = (diskfile_header *)snapshot;

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	/* strmap_begin() is currently a macro returning 0 */
	GIT_UNUSED(h);

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	it->parent.backend = snapshot;
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	it->iter = git_strmap_begin(h->values);
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	it->next_var = NULL;

	it->parent.next = config_iterator_next;
	it->parent.free = config_iterator_free;
	*iter = (git_config_iterator *) it;
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	return 0;
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}

Ben Straub committed
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static int config_set(git_config_backend *cfg, const char *name, const char *value)
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{
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	diskfile_backend *b = (diskfile_backend *)cfg;
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	refcounted_strmap *map;
	git_strmap *values;
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	char *key, *esc_value = NULL;
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	khiter_t pos;
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	int rval, ret;
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459
	if ((rval = git_config__normalize_name(name, &key)) < 0)
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		return rval;
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	map = refcounted_strmap_take(&b->header);
	values = map->values;

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	/*
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	 * Try to find it in the existing values and update it if it
	 * only has one value.
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	 */
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	pos = git_strmap_lookup_index(values, key);
	if (git_strmap_valid_index(values, pos)) {
		cvar_t *existing = git_strmap_value_at(values, pos);
Russell Belfer committed
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		if (existing->next != NULL) {
			giterr_set(GITERR_CONFIG, "Multivar incompatible with simple set");
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			ret = -1;
			goto out;
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		}
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Russell Belfer committed
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		/* don't update if old and new values already match */
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		if ((!existing->entry->value && !value) ||
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			(existing->entry->value && value &&
			 !strcmp(existing->entry->value, value))) {
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			ret = 0;
			goto out;
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		}
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	}

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	/* No early returns due to sanity checks, let's write it out and refresh */
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	if (value) {
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		esc_value = escape_value(value);
		GITERR_CHECK_ALLOC(esc_value);
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	}

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	if ((ret = config_write(b, key, NULL, esc_value)) < 0)
		goto out;
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	ret = config_refresh(cfg);
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out:
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	refcounted_strmap_free(map);
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	git__free(esc_value);
	git__free(key);
	return ret;
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}

/*
 * Internal function that actually gets the value in string form
 */
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static int config_get(git_config_backend *cfg, const char *key, const git_config_entry **out)
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{
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	diskfile_header *h = (diskfile_header *)cfg;
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	refcounted_strmap *map;
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	git_strmap *values;
	khiter_t pos;
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	cvar_t *var;
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	int error;

	if (!h->readonly && ((error = config_refresh(cfg)) < 0))
		return error;

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	map = refcounted_strmap_take(h);
	values = map->values;

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	pos = git_strmap_lookup_index(values, key);
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	/* no error message; the config system will write one */
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	if (!git_strmap_valid_index(values, pos)) {
		refcounted_strmap_free(map);
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		return GIT_ENOTFOUND;
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	}
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	var = git_strmap_value_at(values, pos);
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	while (var->next)
		var = var->next;

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	refcounted_strmap_free(map);
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	*out = var->entry;
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	return 0;
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}

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static int config_set_multivar(
Ben Straub committed
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	git_config_backend *cfg, const char *name, const char *regexp, const char *value)
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{
	diskfile_backend *b = (diskfile_backend *)cfg;
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	refcounted_strmap *map;
	git_strmap *values;
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	char *key;
	regex_t preg;
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	int result;
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	khiter_t pos;
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	assert(regexp);
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	if ((result = git_config__normalize_name(name, &key)) < 0)
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		return result;
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	map = refcounted_strmap_take(&b->header);
	values = b->header.values->values;

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	pos = git_strmap_lookup_index(values, key);
	if (!git_strmap_valid_index(values, pos)) {
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		/* If we don't have it, behave like a normal set */
		result = config_set(cfg, name, value);
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		refcounted_strmap_free(map);
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		git__free(key);
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		return result;
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	}
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	result = regcomp(&preg, regexp, REG_EXTENDED);
	if (result < 0) {
		giterr_set_regex(&preg, result);
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		result = -1;
		goto out;
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	}
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	/* If we do have it, set call config_write() and reload */
	if ((result = config_write(b, key, &preg, value)) < 0)
		goto out;
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	result = config_refresh(cfg);
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out:
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	refcounted_strmap_free(map);
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	git__free(key);
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	regfree(&preg);
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	return result;
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}

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static int config_delete(git_config_backend *cfg, const char *name)
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{
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	cvar_t *var;
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	diskfile_backend *b = (diskfile_backend *)cfg;
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	refcounted_strmap *map;	git_strmap *values;
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	char *key;
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	int result;
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	khiter_t pos;
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	if ((result = git_config__normalize_name(name, &key)) < 0)
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		return result;
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	map = refcounted_strmap_take(&b->header);
	values = b->header.values->values;

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	pos = git_strmap_lookup_index(values, key);
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	git__free(key);
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	if (!git_strmap_valid_index(values, pos)) {
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		refcounted_strmap_free(map);
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		giterr_set(GITERR_CONFIG, "Could not find key '%s' to delete", name);
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		return GIT_ENOTFOUND;
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	}
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	var = git_strmap_value_at(values, pos);
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	refcounted_strmap_free(map);
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	if (var->next != NULL) {
		giterr_set(GITERR_CONFIG, "Cannot delete multivar with a single delete");
		return -1;
	}
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	if ((result = config_write(b, var->entry->name, NULL, NULL)) < 0)
		return result;
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	return config_refresh(cfg);
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}

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static int config_delete_multivar(git_config_backend *cfg, const char *name, const char *regexp)
{
	diskfile_backend *b = (diskfile_backend *)cfg;
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	refcounted_strmap *map;
	git_strmap *values;
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	char *key;
	regex_t preg;
	int result;
	khiter_t pos;

	if ((result = git_config__normalize_name(name, &key)) < 0)
		return result;

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	map = refcounted_strmap_take(&b->header);
	values = b->header.values->values;

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	pos = git_strmap_lookup_index(values, key);
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647
	if (!git_strmap_valid_index(values, pos)) {
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		refcounted_strmap_free(map);
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		git__free(key);
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		giterr_set(GITERR_CONFIG, "Could not find key '%s' to delete", name);
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		return GIT_ENOTFOUND;
	}

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	refcounted_strmap_free(map);

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	result = regcomp(&preg, regexp, REG_EXTENDED);
	if (result < 0) {
		giterr_set_regex(&preg, result);
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		result = -1;
		goto out;
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	}

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	if ((result = config_write(b, key, &preg, NULL)) < 0)
		goto out;
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	result = config_refresh(cfg);
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out:
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	git__free(key);
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	regfree(&preg);
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	return result;
}

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static int config_snapshot(git_config_backend **out, git_config_backend *in)
{
	diskfile_backend *b = (diskfile_backend *) in;

	return git_config_file__snapshot(out, b);
}

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int git_config_file__ondisk(git_config_backend **out, const char *path)
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{
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	diskfile_backend *backend;
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	backend = git__calloc(1, sizeof(diskfile_backend));
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	GITERR_CHECK_ALLOC(backend);
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	backend->header.parent.version = GIT_CONFIG_BACKEND_VERSION;
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	git_mutex_init(&backend->header.values_mutex);
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	backend->file_path = git__strdup(path);
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	GITERR_CHECK_ALLOC(backend->file_path);
693

694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752
	backend->header.parent.open = config_open;
	backend->header.parent.get = config_get;
	backend->header.parent.set = config_set;
	backend->header.parent.set_multivar = config_set_multivar;
	backend->header.parent.del = config_delete;
	backend->header.parent.del_multivar = config_delete_multivar;
	backend->header.parent.iterator = config_iterator_new;
	backend->header.parent.snapshot = config_snapshot;
	backend->header.parent.free = backend_free;

	*out = (git_config_backend *)backend;

	return 0;
}

static int config_set_readonly(git_config_backend *cfg, const char *name, const char *value)
{
	GIT_UNUSED(cfg);
	GIT_UNUSED(name);
	GIT_UNUSED(value);

	return config_error_readonly();
}

static int config_set_multivar_readonly(
	git_config_backend *cfg, const char *name, const char *regexp, const char *value)
{
	GIT_UNUSED(cfg);
	GIT_UNUSED(name);
	GIT_UNUSED(regexp);
	GIT_UNUSED(value);

	return config_error_readonly();
}

static int config_delete_multivar_readonly(git_config_backend *cfg, const char *name, const char *regexp)
{
	GIT_UNUSED(cfg);
	GIT_UNUSED(name);
	GIT_UNUSED(regexp);

	return config_error_readonly();
}

static int config_delete_readonly(git_config_backend *cfg, const char *name)
{
	GIT_UNUSED(cfg);
	GIT_UNUSED(name);

	return config_error_readonly();
}

static void backend_readonly_free(git_config_backend *_backend)
{
	diskfile_backend *backend = (diskfile_backend *)_backend;

	if (backend == NULL)
		return;

753
	refcounted_strmap_free(backend->header.values);
754
	git_mutex_free(&backend->header.values_mutex);
755 756 757 758 759 760 761
	git__free(backend);
}

static int config_readonly_open(git_config_backend *cfg, git_config_level_t level)
{
	diskfile_readonly_backend *b = (diskfile_readonly_backend *) cfg;
	diskfile_backend *src = b->snapshot_from;
762
	diskfile_header *src_header = &src->header;
763
	refcounted_strmap *src_map;
764 765 766 767
	int error;

	if (!src_header->readonly && (error = config_refresh(&src_header->parent)) < 0)
		return error;
768 769 770 771

	/* We're just copying data, don't care about the level */
	GIT_UNUSED(level);

772
	src_map = refcounted_strmap_take(src_header);
773
	b->header.values = src_map;
774

775
	return 0;
776 777 778 779 780 781 782 783 784 785
}

int git_config_file__snapshot(git_config_backend **out, diskfile_backend *in)
{
	diskfile_readonly_backend *backend;

	backend = git__calloc(1, sizeof(diskfile_readonly_backend));
	GITERR_CHECK_ALLOC(backend);

	backend->header.parent.version = GIT_CONFIG_BACKEND_VERSION;
786
	git_mutex_init(&backend->header.values_mutex);
787 788 789

	backend->snapshot_from = in;

790
	backend->header.readonly = 1;
791 792 793 794 795 796 797 798 799
	backend->header.parent.version = GIT_CONFIG_BACKEND_VERSION;
	backend->header.parent.open = config_readonly_open;
	backend->header.parent.get = config_get;
	backend->header.parent.set = config_set_readonly;
	backend->header.parent.set_multivar = config_set_multivar_readonly;
	backend->header.parent.del = config_delete_readonly;
	backend->header.parent.del_multivar = config_delete_multivar_readonly;
	backend->header.parent.iterator = config_iterator_new;
	backend->header.parent.free = backend_readonly_free;
800

Ben Straub committed
801
	*out = (git_config_backend *)backend;
802

803
	return 0;
804 805
}

806
static int reader_getchar_raw(struct reader *reader)
807 808 809
{
	int c;

810
	c = *reader->read_ptr++;
811 812 813 814 815

	/*
	Win 32 line breaks: if we find a \r\n sequence,
	return only the \n as a newline
	*/
816 817
	if (c == '\r' && *reader->read_ptr == '\n') {
		reader->read_ptr++;
818 819 820 821
		c = '\n';
	}

	if (c == '\n')
822
		reader->line_number++;
823 824

	if (c == 0) {
825
		reader->eof = 1;
826 827 828 829 830 831 832 833 834
		c = '\n';
	}

	return c;
}

#define SKIP_WHITESPACE (1 << 1)
#define SKIP_COMMENTS (1 << 2)

835
static int reader_getchar(struct reader *reader, int flags)
836 837 838 839 840
{
	const int skip_whitespace = (flags & SKIP_WHITESPACE);
	const int skip_comments = (flags & SKIP_COMMENTS);
	int c;

841
	assert(reader->read_ptr);
842

843 844 845 846
	do {
		c = reader_getchar_raw(reader);
	} while (skip_whitespace && git__isspace(c) &&
	       !reader->eof);
847 848

	if (skip_comments && (c == '#' || c == ';')) {
849 850 851
		do {
			c = reader_getchar_raw(reader);
		} while (c != '\n');
852 853 854 855 856 857 858 859
	}

	return c;
}

/*
 * Read the next char, but don't move the reading pointer.
 */
860
static int reader_peek(struct reader *reader, int flags)
861 862 863 864 865
{
	void *old_read_ptr;
	int old_lineno, old_eof;
	int ret;

866
	assert(reader->read_ptr);
867

868 869 870
	old_read_ptr = reader->read_ptr;
	old_lineno = reader->line_number;
	old_eof = reader->eof;
871

872
	ret = reader_getchar(reader, flags);
873

874 875 876
	reader->read_ptr = old_read_ptr;
	reader->line_number = old_lineno;
	reader->eof = old_eof;
877 878 879 880 881 882 883

	return ret;
}

/*
 * Read and consume a line, returning it in newly-allocated memory.
 */
884
static char *reader_readline(struct reader *reader, bool skip_whitespace)
885 886 887
{
	char *line = NULL;
	char *line_src, *line_end;
888
	size_t line_len;
889

890
	line_src = reader->read_ptr;
891

892 893
	if (skip_whitespace) {
		/* Skip empty empty lines */
894
		while (git__isspace(*line_src))
895 896
			++line_src;
	}
897

898
	line_end = strchr(line_src, '\n');
899

900
	/* no newline at EOF */
901 902 903
	if (line_end == NULL)
		line_end = strchr(line_src, 0);

904
	line_len = line_end - line_src;
905

906
	line = git__malloc(line_len + 1);
907 908 909
	if (line == NULL)
		return NULL;

910
	memcpy(line, line_src, line_len);
911

912
	do line[line_len] = '\0';
913
	while (line_len-- > 0 && git__isspace(line[line_len]));
914 915 916 917 918

	if (*line_end == '\n')
		line_end++;

	if (*line_end == '\0')
919
		reader->eof = 1;
920

921 922
	reader->line_number++;
	reader->read_ptr = line_end;
923 924 925 926 927 928 929

	return line;
}

/*
 * Consume a line, without storing it anywhere
 */
930
static void reader_consume_line(struct reader *reader)
931 932 933
{
	char *line_start, *line_end;

934
	line_start = reader->read_ptr;
935 936 937 938 939 940 941 942 943 944
	line_end = strchr(line_start, '\n');
	/* No newline at EOF */
	if(line_end == NULL){
		line_end = strchr(line_start, '\0');
	}

	if (*line_end == '\n')
		line_end++;

	if (*line_end == '\0')
945
		reader->eof = 1;
946

947 948
	reader->line_number++;
	reader->read_ptr = line_end;
949 950
}

951
GIT_INLINE(int) config_keychar(int c)
952 953 954 955
{
	return isalnum(c) || c == '-';
}

956
static int parse_section_header_ext(struct reader *reader, const char *line, const char *base_name, char **section_name)
957
{
958 959 960
	int c, rpos;
	char *first_quote, *last_quote;
	git_buf buf = GIT_BUF_INIT;
961 962 963 964 965 966 967 968 969
	/*
	 * base_name is what came before the space. We should be at the
	 * first quotation mark, except for now, line isn't being kept in
	 * sync so we only really use it to calculate the length.
	 */

	first_quote = strchr(line, '"');
	last_quote = strrchr(line, '"');

970
	if (last_quote - first_quote == 0) {
971
		set_parse_error(reader, 0, "Missing closing quotation mark in section header");
972 973
		return -1;
	}
974

975 976
	git_buf_grow(&buf, strlen(base_name) + last_quote - first_quote + 2);
	git_buf_printf(&buf, "%s.", base_name);
977 978 979 980

	rpos = 0;

	line = first_quote;
981
	c = line[++rpos];
982 983 984 985 986 987

	/*
	 * At the end of each iteration, whatever is stored in c will be
	 * added to the string. In case of error, jump to out
	 */
	do {
988

989
		switch (c) {
990
		case 0:
991
			set_parse_error(reader, 0, "Unexpected end-of-line in section header");
992 993 994
			git_buf_free(&buf);
			return -1;

995
		case '"':
996
			goto end_parse;
997

998
		case '\\':
999
			c = line[++rpos];
1000

1001 1002
			if (c == 0) {
				set_parse_error(reader, rpos, "Unexpected end-of-line in section header");
1003 1004
				git_buf_free(&buf);
				return -1;
1005
			}
1006

1007 1008 1009 1010
		default:
			break;
		}

Linquize committed
1011
		git_buf_putc(&buf, (char)c);
1012 1013 1014 1015 1016 1017 1018 1019 1020
		c = line[++rpos];
	} while (line + rpos < last_quote);

end_parse:
	if (line[rpos] != '"' || line[rpos + 1] != ']') {
		set_parse_error(reader, rpos, "Unexpected text after closing quotes");
		git_buf_free(&buf);
		return -1;
	}
1021

1022 1023
	*section_name = git_buf_detach(&buf);
	return 0;
1024 1025
}

1026
static int parse_section_header(struct reader *reader, char **section_out)
1027 1028 1029
{
	char *name, *name_end;
	int name_length, c, pos;
1030
	int result;
1031 1032
	char *line;

1033
	line = reader_readline(reader, true);
1034
	if (line == NULL)
1035
		return -1;
1036 1037

	/* find the end of the variable's name */
1038
	name_end = strrchr(line, ']');
schu committed
1039
	if (name_end == NULL) {
1040
		git__free(line);
1041
		set_parse_error(reader, 0, "Missing ']' in section header");
1042
		return -1;
schu committed
1043
	}
1044 1045

	name = (char *)git__malloc((size_t)(name_end - line) + 1);
1046
	GITERR_CHECK_ALLOC(name);
1047 1048 1049 1050 1051 1052

	name_length = 0;
	pos = 0;

	/* Make sure we were given a section header */
	c = line[pos++];
1053
	assert(c == '[');
1054 1055 1056 1057

	c = line[pos++];

	do {
1058
		if (git__isspace(c)){
1059
			name[name_length] = '\0';
1060
			result = parse_section_header_ext(reader, line, name, section_out);
1061 1062
			git__free(line);
			git__free(name);
1063
			return result;
1064 1065 1066
		}

		if (!config_keychar(c) && c != '.') {
1067
			set_parse_error(reader, pos, "Unexpected character in header");
1068
			goto fail_parse;
1069 1070
		}

1071
		name[name_length++] = (char) tolower(c);
1072 1073 1074

	} while ((c = line[pos++]) != ']');

schu committed
1075
	if (line[pos - 1] != ']') {
1076
		set_parse_error(reader, pos, "Unexpected end of file");
1077
		goto fail_parse;
schu committed
1078
	}
1079

1080
	git__free(line);
1081 1082

	name[name_length] = 0;
1083 1084
	*section_out = name;

1085 1086 1087
	return 0;

fail_parse:
1088 1089
	git__free(line);
	git__free(name);
1090
	return -1;
1091 1092
}

1093
static int skip_bom(struct reader *reader)
1094
{
1095 1096
	git_bom_t bom;
	int bom_offset = git_buf_text_detect_bom(&bom,
1097
		&reader->buffer, reader->read_ptr - reader->buffer.ptr);
1098

1099
	if (bom == GIT_BOM_UTF8)
1100
		reader->read_ptr += bom_offset;
1101

1102
	/* TODO: reference implementation is pretty stupid with BoM */
1103

1104
	return 0;
1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145
}

/*
	(* basic types *)
	digit = "0".."9"
	integer = digit { digit }
	alphabet = "a".."z" + "A" .. "Z"

	section_char = alphabet | "." | "-"
	extension_char = (* any character except newline *)
	any_char = (* any character *)
	variable_char = "alphabet" | "-"


	(* actual grammar *)
	config = { section }

	section = header { definition }

	header = "[" section [subsection | subsection_ext] "]"

	subsection = "." section
	subsection_ext = "\"" extension "\""

	section = section_char { section_char }
	extension = extension_char { extension_char }

	definition = variable_name ["=" variable_value] "\n"

	variable_name = variable_char { variable_char }
	variable_value = string | boolean | integer

	string = quoted_string | plain_string
	quoted_string = "\"" plain_string "\""
	plain_string = { any_char }

	boolean = boolean_true | boolean_false
	boolean_true = "yes" | "1" | "true" | "on"
	boolean_false = "no" | "0" | "false" | "off"
*/

1146
static int strip_comments(char *line, int in_quotes)
1147
{
1148
	int quote_count = in_quotes;
1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160
	char *ptr;

	for (ptr = line; *ptr; ++ptr) {
		if (ptr[0] == '"' && ptr > line && ptr[-1] != '\\')
			quote_count++;

		if ((ptr[0] == ';' || ptr[0] == '#') && (quote_count % 2) == 0) {
			ptr[0] = '\0';
			break;
		}
	}

1161
	/* skip any space at the end */
1162
	while (ptr > line && git__isspace(ptr[-1])) {
1163
		ptr--;
1164
	}
1165 1166 1167
	ptr[0] = '\0';

	return quote_count;
1168 1169
}

1170 1171 1172 1173
static int included_path(git_buf *out, const char *dir, const char *path)
{
	/* From the user's home */
	if (path[0] == '~' && path[1] == '/')
1174
		return git_sysdir_find_global_file(out, &path[1]);
1175 1176 1177 1178

	return git_path_join_unrooted(out, path, dir, NULL);
}

1179
static int config_parse(git_strmap *values, diskfile_backend *cfg_file, struct reader *reader, git_config_level_t level, int depth)
1180
{
1181
	int c;
1182 1183 1184
	char *current_section = NULL;
	char *var_name;
	char *var_value;
1185
	cvar_t *var;
1186
	git_buf buf = GIT_BUF_INIT;
1187
	int result = 0;
1188
	uint32_t reader_idx;
1189

1190 1191 1192 1193
	if (depth >= MAX_INCLUDE_DEPTH) {
		giterr_set(GITERR_CONFIG, "Maximum config include depth reached");
		return -1;
	}
1194

1195
	reader_idx = git_array_size(cfg_file->readers) - 1;
1196
	/* Initialize the reading position */
1197 1198
	reader->read_ptr = reader->buffer.ptr;
	reader->eof = 0;
1199

1200
	/* If the file is empty, there's nothing for us to do */
1201
	if (*reader->read_ptr == '\0')
1202
		return 0;
1203

1204
	skip_bom(reader);
1205

1206
	while (result == 0 && !reader->eof) {
1207

1208
		c = reader_peek(reader, SKIP_WHITESPACE);
1209 1210

		switch (c) {
1211
		case '\n': /* EOF when peeking, set EOF in the reader to exit the loop */
1212
			reader->eof = 1;
1213 1214 1215
			break;

		case '[': /* section header, new section begins */
1216
			git__free(current_section);
1217
			current_section = NULL;
1218
			result = parse_section_header(reader, &current_section);
1219 1220 1221 1222
			break;

		case ';':
		case '#':
1223
			reader_consume_line(reader);
1224 1225 1226
			break;

		default: /* assume variable declaration */
1227
			result = parse_variable(reader, &var_name, &var_value);
1228
			if (result < 0)
1229 1230
				break;

1231 1232 1233 1234
			git__strtolower(var_name);
			git_buf_printf(&buf, "%s.%s", current_section, var_name);
			git__free(var_name);

1235 1236
			if (git_buf_oom(&buf)) {
				git__free(var_value);
1237
				return -1;
1238
			}
1239

Jacques Germishuys committed
1240 1241 1242 1243 1244
			var = git__calloc(1, sizeof(cvar_t));
			GITERR_CHECK_ALLOC(var);
			var->entry = git__calloc(1, sizeof(git_config_entry));
			GITERR_CHECK_ALLOC(var->entry);

1245 1246 1247
			var->entry->name = git_buf_detach(&buf);
			var->entry->value = var_value;
			var->entry->level = level;
1248
			var->included = !!depth;
1249

1250 1251 1252 1253

			if ((result = append_entry(values, var)) < 0)
				break;
			else
1254
				result = 0;
1255

1256
			/* Add or append the new config option */
1257
			if (!git__strcmp(var->entry->name, "include.path")) {
1258
				struct reader *r;
1259 1260
				git_buf path = GIT_BUF_INIT;
				char *dir;
1261
				uint32_t index;
1262

1263
				r = git_array_alloc(cfg_file->readers);
1264 1265
				/* The reader may have been reallocated */
				reader = git_array_get(cfg_file->readers, reader_idx);
1266
				memset(r, 0, sizeof(struct reader));
1267 1268 1269
				if ((result = git_path_dirname_r(&path, reader->file_path)) < 0)
					break;

1270
				/* We need to know our index in the array, as the next config_parse call may realloc */
1271
				index = git_array_size(cfg_file->readers) - 1;
1272 1273 1274 1275 1276 1277 1278
				dir = git_buf_detach(&path);
				result = included_path(&path, dir, var->entry->value);
				git__free(dir);

				if (result < 0)
					break;

1279 1280
				r->file_path = git_buf_detach(&path);
				git_buf_init(&r->buffer, 0);
1281 1282 1283 1284
				result = git_futils_readbuffer_updated(&r->buffer, r->file_path, &r->file_mtime,
									    &r->file_size, NULL);

				if (result == 0) {
1285 1286
					result = config_parse(values, cfg_file, r, level, depth+1);
					r = git_array_get(cfg_file->readers, index);
1287
					reader = git_array_get(cfg_file->readers, reader_idx);
1288
				}
1289 1290 1291 1292 1293
				else if (result == GIT_ENOTFOUND) {
					giterr_clear();
					result = 0;
				}

1294
				git_buf_free(&r->buffer);
1295 1296 1297 1298 1299

				if (result < 0)
					break;
			}

1300 1301 1302 1303
			break;
		}
	}

1304
	git__free(current_section);
1305
	return result;
1306 1307
}

1308
static int write_section(git_filebuf *file, const char *key)
1309
{
1310
	int result;
1311
	const char *dot;
1312
	git_buf buf = GIT_BUF_INIT;
1313

1314
	/* All of this just for [section "subsection"] */
1315
	dot = strchr(key, '.');
1316
	git_buf_putc(&buf, '[');
1317
	if (dot == NULL) {
1318
		git_buf_puts(&buf, key);
1319
	} else {
1320
		char *escaped;
1321
		git_buf_put(&buf, key, dot - key);
1322 1323 1324 1325
		escaped = escape_value(dot + 1);
		GITERR_CHECK_ALLOC(escaped);
		git_buf_printf(&buf, " \"%s\"", escaped);
		git__free(escaped);
1326 1327
	}
	git_buf_puts(&buf, "]\n");
1328

1329
	if (git_buf_oom(&buf))
1330
		return -1;
1331

1332
	result = git_filebuf_write(file, git_buf_cstr(&buf), buf.size);
1333
	git_buf_free(&buf);
1334

1335
	return result;
1336 1337
}

Vicent Marti committed
1338
static const char *quotes_for_value(const char *value)
1339
{
Vicent Marti committed
1340 1341 1342 1343 1344 1345
	const char *ptr;

	if (value[0] == ' ' || value[0] == '\0')
		return "\"";

	for (ptr = value; *ptr; ++ptr) {
1346
		if (*ptr == ';' || *ptr == '#')
Vicent Marti committed
1347
			return "\"";
1348 1349
	}

Vicent Marti committed
1350 1351 1352 1353
	if (ptr[-1] == ' ')
		return "\"";

	return "";
1354 1355
}

1356 1357 1358
/*
 * This is pretty much the parsing, except we write out anything we don't have
 */
1359
static int config_write(diskfile_backend *cfg, const char *key, const regex_t *preg, const char* value)
1360
{
1361 1362
	int result, c;
	int section_matches = 0, last_section_matched = 0, preg_replaced = 0, write_trailer = 0;
1363
	const char *pre_end = NULL, *post_start = NULL, *data_start, *write_start;
1364
	char *current_section = NULL, *section, *name, *ldot;
1365
	git_filebuf file = GIT_FILEBUF_INIT;
1366
	struct reader *reader = git_array_get(cfg->readers, 0);
1367 1368

	/* We need to read in our own config file */
1369
	result = git_futils_readbuffer(&reader->buffer, cfg->file_path);
1370 1371

	/* Initialise the reading position */
1372
	if (result == GIT_ENOTFOUND) {
1373 1374
		reader->read_ptr = NULL;
		reader->eof = 1;
1375
		data_start = NULL;
1376
		git_buf_clear(&reader->buffer);
1377
	} else if (result == 0) {
1378 1379 1380
		reader->read_ptr = reader->buffer.ptr;
		reader->eof = 0;
		data_start = reader->read_ptr;
1381 1382
	} else {
		return -1; /* OS error when reading the file */
1383
	}
1384

1385 1386
	write_start = data_start;

1387
	/* Lock the file */
nulltoken committed
1388 1389 1390 1391 1392
	if ((result = git_filebuf_open(
		&file, cfg->file_path, 0, GIT_CONFIG_FILE_MODE)) < 0) {
			git_buf_free(&reader->buffer);
			return result;
	}
1393

1394
	skip_bom(reader);
1395 1396 1397
	ldot = strrchr(key, '.');
	name = ldot + 1;
	section = git__strndup(key, ldot - key);
1398

1399 1400
	while (!reader->eof) {
		c = reader_peek(reader, SKIP_WHITESPACE);
1401

1402
		if (c == '\0') { /* We've arrived at the end of the file */
1403 1404
			break;

1405
		} else if (c == '[') { /* section header, new section begins */
1406 1407 1408 1409 1410 1411 1412
			/*
			 * We set both positions to the current one in case we
			 * need to add a variable to the end of a section. In that
			 * case, we want both variables to point just before the
			 * new section. If we actually want to replace it, the
			 * default case will take care of updating them.
			 */
1413
			pre_end = post_start = reader->read_ptr;
1414 1415

			git__free(current_section);
1416
			current_section = NULL;
1417
			if (parse_section_header(reader, &current_section) < 0)
1418
				goto rewrite_fail;
1419 1420 1421

			/* Keep track of when it stops matching */
			last_section_matched = section_matches;
1422
			section_matches = !strcmp(current_section, section);
1423
		}
1424

1425
		else if (c == ';' || c == '#') {
1426
			reader_consume_line(reader);
1427
		}
1428

1429
		else {
1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441
			/*
			 * If the section doesn't match, but the last section did,
			 * it means we need to add a variable (so skip the line
			 * otherwise). If both the section and name match, we need
			 * to overwrite the variable (so skip the line
			 * otherwise). pre_end needs to be updated each time so we
			 * don't loose that information, but we only need to
			 * update post_start if we're going to use it in this
			 * iteration.
			 */
			if (!section_matches) {
				if (!last_section_matched) {
1442
					reader_consume_line(reader);
1443
					continue;
1444 1445
				}
			} else {
1446 1447
				int has_matched = 0;
				char *var_name, *var_value;
1448

1449 1450
				pre_end = reader->read_ptr;
				if (parse_variable(reader, &var_name, &var_value) < 0)
1451
					goto rewrite_fail;
1452

1453 1454 1455
				/* First try to match the name of the variable */
				if (strcasecmp(name, var_name) == 0)
					has_matched = 1;
1456

1457 1458 1459 1460
				/* If the name matches, and we have a regex to match the
				 * value, try to match it */
				if (has_matched && preg != NULL)
					has_matched = (regexec(preg, var_value, 0, NULL, 0) == 0);
1461

1462 1463
				git__free(var_name);
				git__free(var_value);
1464

1465 1466 1467
				/* if there is no match, keep going */
				if (!has_matched)
					continue;
1468

1469
				post_start = reader->read_ptr;
1470 1471
			}

1472 1473
			/* We've found the variable we wanted to change, so
			 * write anything up to it */
1474
			git_filebuf_write(&file, write_start, pre_end - write_start);
1475
			preg_replaced = 1;
1476

1477 1478 1479
			/* Then replace the variable. If the value is NULL, it
			 * means we want to delete it, so don't write anything. */
			if (value != NULL) {
Vicent Marti committed
1480 1481
				const char *q = quotes_for_value(value);
				git_filebuf_printf(&file, "\t%s = %s%s%s\n", name, q, value, q);
1482 1483
			}

1484 1485 1486 1487 1488 1489 1490
			/*
			 * If we have a multivar, we should keep looking for entries,
			 * but only if we're in the right section. Otherwise we'll end up
			 * looping on the edge of a matching and a non-matching section.
			 */
			if (section_matches && preg != NULL) {
				write_start = post_start;
1491 1492 1493
				continue;
			}

1494 1495
			write_trailer = 1;
			break; /* break from the loop */
1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507
		}
	}

	/*
	 * Being here can mean that
	 *
	 * 1) our section is the last one in the file and we're
	 * adding a variable
	 *
	 * 2) we didn't find a section for us so we need to create it
	 * ourselves.
	 *
1508 1509 1510 1511 1512 1513
	 * 3) we're setting a multivar with a regex, which means we
	 * continue to search for matching values
	 *
	 * In the last case, if we've already replaced a value, we
	 * want to write the rest of the file. Otherwise we need to write
	 * out the whole file and then the new variable.
1514
	 */
1515 1516
	if (write_trailer) {
		/* Write out rest of the file */
1517
		git_filebuf_write(&file, post_start, reader->buffer.size - (post_start - data_start));
1518 1519
	} else {
		if (preg_replaced) {
1520
			git_filebuf_printf(&file, "\n%s", write_start);
1521
		} else {
Vicent Marti committed
1522 1523
			const char *q;

1524
			git_filebuf_write(&file, reader->buffer.ptr, reader->buffer.size);
1525

1526 1527 1528
			if (reader->buffer.size > 0 && *(reader->buffer.ptr + reader->buffer.size - 1) != '\n')
				git_filebuf_write(&file, "\n", 1);

1529 1530 1531 1532 1533
			/* And now if we just need to add a variable */
			if (!section_matches && write_section(&file, section) < 0)
				goto rewrite_fail;

			/* Sanity check: if we are here, and value is NULL, that means that somebody
Will Stamper committed
1534
			 * touched the config file after our initial read. We should probably assert()
1535 1536 1537
			 * this, but instead we'll handle it gracefully with an error. */
			if (value == NULL) {
				giterr_set(GITERR_CONFIG,
1538
					"race condition when writing a config file (a cvar has been removed)");
1539 1540
				goto rewrite_fail;
			}
1541

1542
			/* If we are here, there is at least a section line */
Vicent Marti committed
1543 1544
			q = quotes_for_value(value);
			git_filebuf_printf(&file, "\t%s = %s%s%s\n", name, q, value, q);
1545
		}
1546 1547
	}

1548 1549
	git__free(section);
	git__free(current_section);
1550

1551
	/* refresh stats - if this errors, then commit will error too */
1552
	(void)git_filebuf_stats(&reader->file_mtime, &reader->file_size, &file);
1553

1554
	result = git_filebuf_commit(&file);
1555
	git_buf_free(&reader->buffer);
1556

1557
	return result;
1558

1559
rewrite_fail:
1560
	git__free(section);
1561
	git__free(current_section);
1562

1563
	git_filebuf_cleanup(&file);
1564
	git_buf_free(&reader->buffer);
1565
	return -1;
1566 1567
}

1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580
static const char *escapes = "ntb\"\\";
static const char *escaped = "\n\t\b\"\\";

/* Escape the values to write them to the file */
static char *escape_value(const char *ptr)
{
	git_buf buf = GIT_BUF_INIT;
	size_t len;
	const char *esc;

	assert(ptr);

	len = strlen(ptr);
1581 1582 1583
	if (!len)
		return git__calloc(1, sizeof(char));

1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603
	git_buf_grow(&buf, len);

	while (*ptr != '\0') {
		if ((esc = strchr(escaped, *ptr)) != NULL) {
			git_buf_putc(&buf, '\\');
			git_buf_putc(&buf, escapes[esc - escaped]);
		} else {
			git_buf_putc(&buf, *ptr);
		}
		ptr++;
	}

	if (git_buf_oom(&buf)) {
		git_buf_free(&buf);
		return NULL;
	}

	return git_buf_detach(&buf);
}

1604 1605
/* '\"' -> '"' etc */
static char *fixup_line(const char *ptr, int quote_count)
1606
{
1607 1608 1609 1610 1611
	char *str = git__malloc(strlen(ptr) + 1);
	char *out = str, *esc;

	if (str == NULL)
		return NULL;
1612

1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641
	while (*ptr != '\0') {
		if (*ptr == '"') {
			quote_count++;
		} else if (*ptr != '\\') {
			*out++ = *ptr;
		} else {
			/* backslash, check the next char */
			ptr++;
			/* if we're at the end, it's a multiline, so keep the backslash */
			if (*ptr == '\0') {
				*out++ = '\\';
				goto out;
			}
			if ((esc = strchr(escapes, *ptr)) != NULL) {
				*out++ = escaped[esc - escapes];
			} else {
				git__free(str);
				giterr_set(GITERR_CONFIG, "Invalid escape at %s", ptr);
				return NULL;
			}
		}
		ptr++;
	}

out:
	*out = '\0';

	return str;
}
1642 1643 1644

static int is_multiline_var(const char *str)
{
1645
	int count = 0;
1646
	const char *end = str + strlen(str);
1647 1648 1649 1650 1651 1652
	while (end > str && end[-1] == '\\') {
		count++;
		end--;
	}

	/* An odd number means last backslash wasn't escaped, so it's multiline */
1653
	return count & 1;
1654 1655
}

1656
static int parse_multiline_variable(struct reader *reader, git_buf *value, int in_quotes)
1657
{
1658 1659
	char *line = NULL, *proc_line = NULL;
	int quote_count;
1660 1661

	/* Check that the next line exists */
1662
	line = reader_readline(reader, false);
1663
	if (line == NULL)
1664
		return -1;
1665 1666 1667

	/* We've reached the end of the file, there is input missing */
	if (line[0] == '\0') {
1668
		set_parse_error(reader, 0, "Unexpected end of file while parsing multine var");
1669 1670
		git__free(line);
		return -1;
1671 1672
	}

1673
	quote_count = strip_comments(line, !!in_quotes);
1674 1675 1676

	/* If it was just a comment, pretend it didn't exist */
	if (line[0] == '\0') {
1677
		git__free(line);
1678
		return parse_multiline_variable(reader, value, quote_count);
1679
		/* TODO: unbounded recursion. This **could** be exploitable */
1680 1681
	}

1682 1683 1684 1685
	/* Drop the continuation character '\': to closely follow the UNIX
	 * standard, this character **has** to be last one in the buf, with
	 * no whitespace after it */
	assert(is_multiline_var(value->ptr));
1686
	git_buf_shorten(value, 1);
1687

1688 1689 1690 1691
	proc_line = fixup_line(line, in_quotes);
	if (proc_line == NULL) {
		git__free(line);
		return -1;
1692
	}
1693
	/* add this line to the multiline var */
1694
	git_buf_puts(value, proc_line);
1695
	git__free(line);
1696
	git__free(proc_line);
1697 1698

	/*
1699 1700
	 * If we need to continue reading the next line, let's just
	 * keep putting stuff in the buffer
1701
	 */
1702
	if (is_multiline_var(value->ptr))
1703
		return parse_multiline_variable(reader, value, quote_count);
1704

1705
	return 0;
1706 1707
}

1708
static int parse_variable(struct reader *reader, char **var_name, char **var_value)
1709 1710 1711 1712
{
	const char *var_end = NULL;
	const char *value_start = NULL;
	char *line;
1713
	int quote_count;
1714

1715
	line = reader_readline(reader, true);
1716
	if (line == NULL)
1717
		return -1;
1718

1719
	quote_count = strip_comments(line, 0);
1720 1721 1722 1723 1724 1725 1726 1727

	var_end = strchr(line, '=');

	if (var_end == NULL)
		var_end = strchr(line, '\0');
	else
		value_start = var_end + 1;

Russell Belfer committed
1728
	do var_end--;
1729
	while (var_end>line && git__isspace(*var_end));
1730

1731 1732
	*var_name = git__strndup(line, var_end - line + 1);
	GITERR_CHECK_ALLOC(*var_name);
1733

1734 1735
	/* If there is no value, boolean true is assumed */
	*var_value = NULL;
1736 1737 1738 1739 1740

	/*
	 * Now, let's try to parse the value
	 */
	if (value_start != NULL) {
1741
		while (git__isspace(value_start[0]))
1742 1743 1744
			value_start++;

		if (is_multiline_var(value_start)) {
1745
			git_buf multi_value = GIT_BUF_INIT;
1746 1747 1748
			char *proc_line = fixup_line(value_start, 0);
			GITERR_CHECK_ALLOC(proc_line);
			git_buf_puts(&multi_value, proc_line);
1749
			git__free(proc_line);
1750
			if (parse_multiline_variable(reader, &multi_value, quote_count) < 0 || git_buf_oom(&multi_value)) {
1751
				git__free(*var_name);
1752 1753 1754
				git__free(line);
				git_buf_free(&multi_value);
				return -1;
1755
			}
1756

1757
			*var_value = git_buf_detach(&multi_value);
1758

1759 1760
		}
		else if (value_start[0] != '\0') {
1761
			*var_value = fixup_line(value_start, 0);
1762
			GITERR_CHECK_ALLOC(*var_value);
1763 1764 1765
		} else { /* equals sign but missing rhs */
			*var_value = git__strdup("");
			GITERR_CHECK_ALLOC(*var_value);
1766 1767 1768
		}
	}

1769
	git__free(line);
1770
	return 0;
1771
}