buffer.c 23.7 KB
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Vicent Marti committed
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/*
Edward Thomson committed
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 * Copyright (C) the libgit2 contributors. All rights reserved.
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 "buffer.h"
#include "posix.h"
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#include "git2/buffer.h"
joshaber committed
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#include "buf_text.h"
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#include <ctype.h>
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/* Used as default value for git_buf->ptr so that people can always
 * assume ptr is non-NULL and zero terminated even for new git_bufs.
 */
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char git_buf__initbuf[1];
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char git_buf__oom[1];
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#define ENSURE_SIZE(b, d) \
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	if ((b)->ptr == git_buf__oom || \
	    ((d) > (b)->asize && git_buf_grow((b), (d)) < 0))\
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		return -1;
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int git_buf_init(git_buf *buf, size_t initial_size)
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{
	buf->asize = 0;
	buf->size = 0;
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	buf->ptr = git_buf__initbuf;
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	ENSURE_SIZE(buf, initial_size);

	return 0;
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}

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int git_buf_try_grow(
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	git_buf *buf, size_t target_size, bool mark_oom)
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{
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	char *new_ptr;
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	size_t new_size;
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	if (buf->ptr == git_buf__oom)
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		return -1;
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	if (buf->asize == 0 && buf->size != 0) {
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		git_error_set(GIT_ERROR_INVALID, "cannot grow a borrowed buffer");
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		return GIT_EINVALID;
	}
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	if (!target_size)
		target_size = buf->size;

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	if (target_size <= buf->asize)
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		return 0;
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	if (buf->asize == 0) {
		new_size = target_size;
		new_ptr = NULL;
	} else {
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		new_size = buf->asize;
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		/*
		 * Grow the allocated buffer by 1.5 to allow
		 * re-use of memory holes resulting from the
		 * realloc. If this is still too small, then just
		 * use the target size.
		 */
		if ((new_size = (new_size << 1) - (new_size >> 1)) < target_size)
			new_size = target_size;
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		new_ptr = buf->ptr;
	}
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	/* round allocation up to multiple of 8 */
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	new_size = (new_size + 7) & ~7;
75

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	if (new_size < buf->size) {
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		if (mark_oom) {
			if (buf->ptr && buf->ptr != git_buf__initbuf)
				git__free(buf->ptr);
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			buf->ptr = git_buf__oom;
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		}
82

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		git_error_set_oom();
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		return -1;
	}

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	new_ptr = git__realloc(new_ptr, new_size);
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	if (!new_ptr) {
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		if (mark_oom) {
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			if (buf->ptr && (buf->ptr != git_buf__initbuf))
				git__free(buf->ptr);
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			buf->ptr = git_buf__oom;
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		}
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		return -1;
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	}
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	buf->asize = new_size;
	buf->ptr   = new_ptr;

	/* truncate the existing buffer size if necessary */
	if (buf->size >= buf->asize)
		buf->size = buf->asize - 1;
	buf->ptr[buf->size] = '\0';

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	return 0;
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}

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int git_buf_grow(git_buf *buffer, size_t target_size)
{
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	return git_buf_try_grow(buffer, target_size, true);
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}

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int git_buf_grow_by(git_buf *buffer, size_t additional_size)
{
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	size_t newsize;

	if (GIT_ADD_SIZET_OVERFLOW(&newsize, buffer->size, additional_size)) {
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		buffer->ptr = git_buf__oom;
		return -1;
	}

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	return git_buf_try_grow(buffer, newsize, true);
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}

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void git_buf_dispose(git_buf *buf)
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{
	if (!buf) return;

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	if (buf->asize > 0 && buf->ptr != NULL && buf->ptr != git_buf__oom)
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		git__free(buf->ptr);

	git_buf_init(buf, 0);
}

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#ifndef GIT_DEPRECATE_HARD
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void git_buf_free(git_buf *buf)
{
	git_buf_dispose(buf);
}
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#endif
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void git_buf_sanitize(git_buf *buf)
{
	if (buf->ptr == NULL) {
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		assert(buf->size == 0 && buf->asize == 0);
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		buf->ptr = git_buf__initbuf;
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	} else if (buf->asize > buf->size)
		buf->ptr[buf->size] = '\0';
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}

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void git_buf_clear(git_buf *buf)
{
	buf->size = 0;
155

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	if (!buf->ptr) {
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		buf->ptr = git_buf__initbuf;
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		buf->asize = 0;
	}
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	if (buf->asize > 0)
		buf->ptr[0] = '\0';
}

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int git_buf_set(git_buf *buf, const void *data, size_t len)
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{
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	size_t alloclen;

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	if (len == 0 || data == NULL) {
		git_buf_clear(buf);
	} else {
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		if (data != buf->ptr) {
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			GIT_ERROR_CHECK_ALLOC_ADD(&alloclen, len, 1);
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			ENSURE_SIZE(buf, alloclen);
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			memmove(buf->ptr, data, len);
		}
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		buf->size = len;
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		if (buf->asize > buf->size)
			buf->ptr[buf->size] = '\0';

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	}
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	return 0;
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}

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int git_buf_is_binary(const git_buf *buf)
{
	return git_buf_text_is_binary(buf);
}

int git_buf_contains_nul(const git_buf *buf)
{
	return git_buf_text_contains_nul(buf);
}

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int git_buf_sets(git_buf *buf, const char *string)
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{
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	return git_buf_set(buf, string, string ? strlen(string) : 0);
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}

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int git_buf_putc(git_buf *buf, char c)
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{
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	size_t new_size;
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	GIT_ERROR_CHECK_ALLOC_ADD(&new_size, buf->size, 2);
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	ENSURE_SIZE(buf, new_size);
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	buf->ptr[buf->size++] = c;
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	buf->ptr[buf->size] = '\0';
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	return 0;
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}

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int git_buf_putcn(git_buf *buf, char c, size_t len)
{
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	size_t new_size;
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	GIT_ERROR_CHECK_ALLOC_ADD(&new_size, buf->size, len);
	GIT_ERROR_CHECK_ALLOC_ADD(&new_size, new_size, 1);
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	ENSURE_SIZE(buf, new_size);
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	memset(buf->ptr + buf->size, c, len);
	buf->size += len;
	buf->ptr[buf->size] = '\0';
	return 0;
}

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int git_buf_put(git_buf *buf, const char *data, size_t len)
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{
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	if (len) {
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		size_t new_size;

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		assert(data);
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		GIT_ERROR_CHECK_ALLOC_ADD(&new_size, buf->size, len);
		GIT_ERROR_CHECK_ALLOC_ADD(&new_size, new_size, 1);
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		ENSURE_SIZE(buf, new_size);
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		memmove(buf->ptr + buf->size, data, len);
		buf->size += len;
		buf->ptr[buf->size] = '\0';
	}
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	return 0;
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}

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int git_buf_puts(git_buf *buf, const char *string)
241
{
242
	assert(string);
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	return git_buf_put(buf, string, strlen(string));
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}

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static const char base64_encode[] =
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	"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";

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int git_buf_encode_base64(git_buf *buf, const char *data, size_t len)
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{
	size_t extra = len % 3;
	uint8_t *write, a, b, c;
	const uint8_t *read = (const uint8_t *)data;
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	size_t blocks = (len / 3) + !!extra, alloclen;

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	GIT_ERROR_CHECK_ALLOC_ADD(&blocks, blocks, 1);
	GIT_ERROR_CHECK_ALLOC_MULTIPLY(&alloclen, blocks, 4);
	GIT_ERROR_CHECK_ALLOC_ADD(&alloclen, alloclen, buf->size);
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	ENSURE_SIZE(buf, alloclen);
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	write = (uint8_t *)&buf->ptr[buf->size];

	/* convert each run of 3 bytes into 4 output bytes */
	for (len -= extra; len > 0; len -= 3) {
		a = *read++;
		b = *read++;
		c = *read++;

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		*write++ = base64_encode[a >> 2];
		*write++ = base64_encode[(a & 0x03) << 4 | b >> 4];
		*write++ = base64_encode[(b & 0x0f) << 2 | c >> 6];
		*write++ = base64_encode[c & 0x3f];
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	}

	if (extra > 0) {
		a = *read++;
		b = (extra > 1) ? *read++ : 0;

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		*write++ = base64_encode[a >> 2];
		*write++ = base64_encode[(a & 0x03) << 4 | b >> 4];
		*write++ = (extra > 1) ? base64_encode[(b & 0x0f) << 2] : '=';
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		*write++ = '=';
	}

	buf->size = ((char *)write) - buf->ptr;
	buf->ptr[buf->size] = '\0';

	return 0;
}

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/* The inverse of base64_encode */
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static const int8_t base64_decode[] = {
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	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63,
	52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1,  0, -1, -1,
	-1,  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14,
	15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1,
	-1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
	41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1,
	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1
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};

int git_buf_decode_base64(git_buf *buf, const char *base64, size_t len)
{
	size_t i;
	int8_t a, b, c, d;
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	size_t orig_size = buf->size, new_size;
316

317
	if (len % 4) {
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		git_error_set(GIT_ERROR_INVALID, "invalid base64 input");
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		return -1;
	}

322
	assert(len % 4 == 0);
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	GIT_ERROR_CHECK_ALLOC_ADD(&new_size, (len / 4 * 3), buf->size);
	GIT_ERROR_CHECK_ALLOC_ADD(&new_size, new_size, 1);
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	ENSURE_SIZE(buf, new_size);
326 327

	for (i = 0; i < len; i += 4) {
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		if ((a = base64_decode[(unsigned char)base64[i]]) < 0 ||
			(b = base64_decode[(unsigned char)base64[i+1]]) < 0 ||
			(c = base64_decode[(unsigned char)base64[i+2]]) < 0 ||
			(d = base64_decode[(unsigned char)base64[i+3]]) < 0) {
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			buf->size = orig_size;
			buf->ptr[buf->size] = '\0';

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			git_error_set(GIT_ERROR_INVALID, "invalid base64 input");
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			return -1;
		}

		buf->ptr[buf->size++] = ((a << 2) | (b & 0x30) >> 4);
		buf->ptr[buf->size++] = ((b & 0x0f) << 4) | ((c & 0x3c) >> 2);
		buf->ptr[buf->size++] = (c & 0x03) << 6 | (d & 0x3f);
	}

	buf->ptr[buf->size] = '\0';
	return 0;
}

348
static const char base85_encode[] =
349 350
	"0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz!#$%&()*+-;<=>?@^_`{|}~";

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int git_buf_encode_base85(git_buf *buf, const char *data, size_t len)
352
{
353
	size_t blocks = (len / 4) + !!(len % 4), alloclen;
354

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	GIT_ERROR_CHECK_ALLOC_MULTIPLY(&alloclen, blocks, 5);
	GIT_ERROR_CHECK_ALLOC_ADD(&alloclen, alloclen, buf->size);
	GIT_ERROR_CHECK_ALLOC_ADD(&alloclen, alloclen, 1);
358 359

	ENSURE_SIZE(buf, alloclen);
360 361 362 363 364 365 366 367

	while (len) {
		uint32_t acc = 0;
		char b85[5];
		int i;

		for (i = 24; i >= 0; i -= 8) {
			uint8_t ch = *data++;
368
			acc |= (uint32_t)ch << i;
369 370 371 372 373 374 375 376 377

			if (--len == 0)
				break;
		}

		for (i = 4; i >= 0; i--) {
			int val = acc % 85;
			acc /= 85;

378
			b85[i] = base85_encode[val];
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		}

		for (i = 0; i < 5; i++)
			buf->ptr[buf->size++] = b85[i];
	}

	buf->ptr[buf->size] = '\0';

	return 0;
}

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/* The inverse of base85_encode */
static const int8_t base85_decode[] = {
	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
	-1, 63, -1, 64, 65, 66, 67, -1, 68, 69, 70, 71, -1, 72, -1, -1,
	 1,  2,  3,  4,  5,  6,  7,  8,  9, 10, -1, 73, 74, 75, 76, 77,
	78, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25,
	26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, -1, -1, -1, 79, 80,
	81, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51,
	52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 82, 83, 84, 85, -1,
	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1
};

int git_buf_decode_base85(
	git_buf *buf,
	const char *base85,
	size_t base85_len,
	size_t output_len)
{
	size_t orig_size = buf->size, new_size;

	if (base85_len % 5 ||
		output_len > base85_len * 4 / 5) {
420
		git_error_set(GIT_ERROR_INVALID, "invalid base85 input");
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		return -1;
	}

424 425
	GIT_ERROR_CHECK_ALLOC_ADD(&new_size, output_len, buf->size);
	GIT_ERROR_CHECK_ALLOC_ADD(&new_size, new_size, 1);
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	ENSURE_SIZE(buf, new_size);

	while (output_len) {
		unsigned acc = 0;
		int de, cnt = 4;
		unsigned char ch;
		do {
			ch = *base85++;
			de = base85_decode[ch];
			if (--de < 0)
				goto on_error;

			acc = acc * 85 + de;
		} while (--cnt);
		ch = *base85++;
		de = base85_decode[ch];
		if (--de < 0)
			goto on_error;

		/* Detect overflow. */
		if (0xffffffff / 85 < acc ||
			0xffffffff - de < (acc *= 85))
			goto on_error;

		acc += de;

452
		cnt = (output_len < 4) ? (int)output_len : 4;
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		output_len -= cnt;
		do {
			acc = (acc << 8) | (acc >> 24);
			buf->ptr[buf->size++] = acc;
		} while (--cnt);
	}

	buf->ptr[buf->size] = 0;

	return 0;

on_error:
	buf->size = orig_size;
	buf->ptr[buf->size] = '\0';

468
	git_error_set(GIT_ERROR_INVALID, "invalid base85 input");
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	return -1;
}

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#define HEX_DECODE(c) ((c | 32) % 39 - 9)

int git_buf_decode_percent(
	git_buf *buf,
	const char *str,
	size_t str_len)
{
	size_t str_pos, new_size;

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	GIT_ERROR_CHECK_ALLOC_ADD(&new_size, buf->size, str_len);
	GIT_ERROR_CHECK_ALLOC_ADD(&new_size, new_size, 1);
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	ENSURE_SIZE(buf, new_size);

	for (str_pos = 0; str_pos < str_len; buf->size++, str_pos++) {
		if (str[str_pos] == '%' &&
			str_len > str_pos + 2 &&
			isxdigit(str[str_pos + 1]) &&
			isxdigit(str[str_pos + 2])) {
			buf->ptr[buf->size] = (HEX_DECODE(str[str_pos + 1]) << 4) +
				HEX_DECODE(str[str_pos + 2]);
			str_pos += 2;
		} else {
			buf->ptr[buf->size] = str[str_pos];
		}
	}

	buf->ptr[buf->size] = '\0';
	return 0;
}

502
int git_buf_vprintf(git_buf *buf, const char *format, va_list ap)
503
{
504
	size_t expected_size, new_size;
505
	int len;
506

507 508
	GIT_ERROR_CHECK_ALLOC_MULTIPLY(&expected_size, strlen(format), 2);
	GIT_ERROR_CHECK_ALLOC_ADD(&expected_size, expected_size, buf->size);
509
	ENSURE_SIZE(buf, expected_size);
510 511

	while (1) {
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		va_list args;
		va_copy(args, ap);

		len = p_vsnprintf(
			buf->ptr + buf->size,
			buf->asize - buf->size,
			format, args
		);
520

521 522
		va_end(args);

523
		if (len < 0) {
524
			git__free(buf->ptr);
525
			buf->ptr = git_buf__oom;
526
			return -1;
527 528
		}

529
		if ((size_t)len + 1 <= buf->asize - buf->size) {
530
			buf->size += len;
531
			break;
532 533
		}

534 535
		GIT_ERROR_CHECK_ALLOC_ADD(&new_size, buf->size, len);
		GIT_ERROR_CHECK_ALLOC_ADD(&new_size, new_size, 1);
536
		ENSURE_SIZE(buf, new_size);
537
	}
538

539
	return 0;
540 541
}

542 543 544 545 546 547 548 549 550 551 552 553
int git_buf_printf(git_buf *buf, const char *format, ...)
{
	int r;
	va_list ap;

	va_start(ap, format);
	r = git_buf_vprintf(buf, format, ap);
	va_end(ap);

	return r;
}

554
void git_buf_copy_cstr(char *data, size_t datasize, const git_buf *buf)
555 556 557
{
	size_t copylen;

558
	assert(data && datasize && buf);
559 560 561 562 563 564 565 566 567 568 569

	data[0] = '\0';

	if (buf->size == 0 || buf->asize <= 0)
		return;

	copylen = buf->size;
	if (copylen > datasize - 1)
		copylen = datasize - 1;
	memmove(data, buf->ptr, copylen);
	data[copylen] = '\0';
570 571
}

572 573 574 575 576
void git_buf_consume_bytes(git_buf *buf, size_t len)
{
	git_buf_consume(buf, buf->ptr + len);
}

577 578
void git_buf_consume(git_buf *buf, const char *end)
{
579 580 581 582
	if (end > buf->ptr && end <= buf->ptr + buf->size) {
		size_t consumed = end - buf->ptr;
		memmove(buf->ptr, end, buf->size - consumed);
		buf->size -= consumed;
583
		buf->ptr[buf->size] = '\0';
584 585 586
	}
}

587
void git_buf_truncate(git_buf *buf, size_t len)
588
{
589 590 591 592 593
	if (len >= buf->size)
		return;

	buf->size = len;
	if (buf->size < buf->asize)
594 595 596
		buf->ptr[buf->size] = '\0';
}

597 598
void git_buf_shorten(git_buf *buf, size_t amount)
{
599 600 601 602
	if (buf->size > amount)
		git_buf_truncate(buf, buf->size - amount);
	else
		git_buf_clear(buf);
603 604
}

605 606
void git_buf_rtruncate_at_char(git_buf *buf, char separator)
{
607 608
	ssize_t idx = git_buf_rfind_next(buf, separator);
	git_buf_truncate(buf, idx < 0 ? 0 : (size_t)idx);
609 610
}

611 612 613 614 615
void git_buf_swap(git_buf *buf_a, git_buf *buf_b)
{
	git_buf t = *buf_a;
	*buf_a = *buf_b;
	*buf_b = t;
616
}
617

618
char *git_buf_detach(git_buf *buf)
619
{
620
	char *data = buf->ptr;
621

622
	if (buf->asize == 0 || buf->ptr == git_buf__oom)
623 624
		return NULL;

625
	git_buf_init(buf, 0);
626 627 628 629

	return data;
}

630
int git_buf_attach(git_buf *buf, char *ptr, size_t asize)
631
{
632
	git_buf_dispose(buf);
633 634 635 636 637 638 639 640 641

	if (ptr) {
		buf->ptr = ptr;
		buf->size = strlen(ptr);
		if (asize)
			buf->asize = (asize < buf->size) ? buf->size + 1 : asize;
		else /* pass 0 to fall back on strlen + 1 */
			buf->asize = buf->size + 1;
	}
642 643 644

	ENSURE_SIZE(buf, asize);
	return 0;
645
}
646

647 648 649
void git_buf_attach_notowned(git_buf *buf, const char *ptr, size_t size)
{
	if (git_buf_is_allocated(buf))
650
		git_buf_dispose(buf);
651 652 653 654 655 656 657 658 659 660

	if (!size) {
		git_buf_init(buf, 0);
	} else {
		buf->ptr = (char *)ptr;
		buf->asize = 0;
		buf->size = size;
	}
}

661 662
int git_buf_join_n(git_buf *buf, char separator, int nbuf, ...)
{
663
	va_list ap;
664
	int i;
665 666
	size_t total_size = 0, original_size = buf->size;
	char *out, *original = buf->ptr;
667 668 669 670

	if (buf->size > 0 && buf->ptr[buf->size - 1] != separator)
		++total_size; /* space for initial separator */

671 672
	/* Make two passes to avoid multiple reallocation */

673 674 675
	va_start(ap, nbuf);
	for (i = 0; i < nbuf; ++i) {
		const char* segment;
676
		size_t segment_len;
677 678 679 680 681 682

		segment = va_arg(ap, const char *);
		if (!segment)
			continue;

		segment_len = strlen(segment);
683

684
		GIT_ERROR_CHECK_ALLOC_ADD(&total_size, total_size, segment_len);
685

686
		if (segment_len == 0 || segment[segment_len - 1] != separator)
687
			GIT_ERROR_CHECK_ALLOC_ADD(&total_size, total_size, 1);
688 689 690
	}
	va_end(ap);

691
	/* expand buffer if needed */
692 693
	if (total_size == 0)
		return 0;
694

695
	GIT_ERROR_CHECK_ALLOC_ADD(&total_size, total_size, 1);
696
	if (git_buf_grow_by(buf, total_size) < 0)
697
		return -1;
698 699 700 701 702 703 704 705 706 707

	out = buf->ptr + buf->size;

	/* append separator to existing buf if needed */
	if (buf->size > 0 && out[-1] != separator)
		*out++ = separator;

	va_start(ap, nbuf);
	for (i = 0; i < nbuf; ++i) {
		const char* segment;
708
		size_t segment_len;
709 710 711 712 713

		segment = va_arg(ap, const char *);
		if (!segment)
			continue;

714 715 716 717 718 719 720 721 722
		/* deal with join that references buffer's original content */
		if (segment >= original && segment < original + original_size) {
			size_t offset = (segment - original);
			segment = buf->ptr + offset;
			segment_len = original_size - offset;
		} else {
			segment_len = strlen(segment);
		}

723 724
		/* skip leading separators */
		if (out > buf->ptr && out[-1] == separator)
725 726 727 728
			while (segment_len > 0 && *segment == separator) {
				segment++;
				segment_len--;
			}
729 730 731 732 733 734 735 736 737 738 739 740 741 742 743

		/* copy over next buffer */
		if (segment_len > 0) {
			memmove(out, segment, segment_len);
			out += segment_len;
		}

		/* append trailing separator (except for last item) */
		if (i < nbuf - 1 && out > buf->ptr && out[-1] != separator)
			*out++ = separator;
	}
	va_end(ap);

	/* set size based on num characters actually written */
	buf->size = out - buf->ptr;
744
	buf->ptr[buf->size] = '\0';
745

746
	return 0;
747 748
}

749
int git_buf_join(
750 751 752 753 754
	git_buf *buf,
	char separator,
	const char *str_a,
	const char *str_b)
{
755
	size_t strlen_a = str_a ? strlen(str_a) : 0;
756
	size_t strlen_b = strlen(str_b);
757
	size_t alloc_len;
758
	int need_sep = 0;
759 760 761
	ssize_t offset_a = -1;

	/* not safe to have str_b point internally to the buffer */
762 763
	if (buf->size)
		assert(str_b < buf->ptr || str_b >= buf->ptr + buf->size);
764 765 766 767 768 769

	/* figure out if we need to insert a separator */
	if (separator && strlen_a) {
		while (*str_b == separator) { str_b++; strlen_b--; }
		if (str_a[strlen_a - 1] != separator)
			need_sep = 1;
770 771
	}

772
	/* str_a could be part of the buffer */
773
	if (buf->size && str_a >= buf->ptr && str_a < buf->ptr + buf->size)
774 775
		offset_a = str_a - buf->ptr;

776 777 778
	GIT_ERROR_CHECK_ALLOC_ADD(&alloc_len, strlen_a, strlen_b);
	GIT_ERROR_CHECK_ALLOC_ADD(&alloc_len, alloc_len, need_sep);
	GIT_ERROR_CHECK_ALLOC_ADD(&alloc_len, alloc_len, 1);
779
	ENSURE_SIZE(buf, alloc_len);
780

781 782 783 784 785
	/* fix up internal pointers */
	if (offset_a >= 0)
		str_a = buf->ptr + offset_a;

	/* do the actual copying */
786
	if (offset_a != 0 && str_a)
787
		memmove(buf->ptr, str_a, strlen_a);
788 789
	if (need_sep)
		buf->ptr[strlen_a] = separator;
790
	memcpy(buf->ptr + strlen_a + need_sep, str_b, strlen_b);
791

792
	buf->size = strlen_a + strlen_b + need_sep;
793
	buf->ptr[buf->size] = '\0';
794

795
	return 0;
796
}
797

798 799 800 801 802 803 804
int git_buf_join3(
	git_buf *buf,
	char separator,
	const char *str_a,
	const char *str_b,
	const char *str_c)
{
805 806 807 808
	size_t len_a = strlen(str_a),
		len_b = strlen(str_b),
		len_c = strlen(str_c),
		len_total;
809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827
	int sep_a = 0, sep_b = 0;
	char *tgt;

	/* for this function, disallow pointers into the existing buffer */
	assert(str_a < buf->ptr || str_a >= buf->ptr + buf->size);
	assert(str_b < buf->ptr || str_b >= buf->ptr + buf->size);
	assert(str_c < buf->ptr || str_c >= buf->ptr + buf->size);

	if (separator) {
		if (len_a > 0) {
			while (*str_b == separator) { str_b++; len_b--; }
			sep_a = (str_a[len_a - 1] != separator);
		}
		if (len_a > 0 || len_b > 0)
			while (*str_c == separator) { str_c++; len_c--; }
		if (len_b > 0)
			sep_b = (str_b[len_b - 1] != separator);
	}

828 829 830 831 832
	GIT_ERROR_CHECK_ALLOC_ADD(&len_total, len_a, sep_a);
	GIT_ERROR_CHECK_ALLOC_ADD(&len_total, len_total, len_b);
	GIT_ERROR_CHECK_ALLOC_ADD(&len_total, len_total, sep_b);
	GIT_ERROR_CHECK_ALLOC_ADD(&len_total, len_total, len_c);
	GIT_ERROR_CHECK_ALLOC_ADD(&len_total, len_total, 1);
833
	ENSURE_SIZE(buf, len_total);
834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857

	tgt = buf->ptr;

	if (len_a) {
		memcpy(tgt, str_a, len_a);
		tgt += len_a;
	}
	if (sep_a)
		*tgt++ = separator;
	if (len_b) {
		memcpy(tgt, str_b, len_b);
		tgt += len_b;
	}
	if (sep_b)
		*tgt++ = separator;
	if (len_c)
		memcpy(tgt, str_c, len_c);

	buf->size = len_a + sep_a + len_b + sep_b + len_c;
	buf->ptr[buf->size] = '\0';

	return 0;
}

858 859 860
void git_buf_rtrim(git_buf *buf)
{
	while (buf->size > 0) {
861
		if (!git__isspace(buf->ptr[buf->size - 1]))
862 863 864 865
			break;

		buf->size--;
	}
866

867 868
	if (buf->asize > buf->size)
		buf->ptr[buf->size] = '\0';
869
}
870 871 872 873 874 875 876

int git_buf_cmp(const git_buf *a, const git_buf *b)
{
	int result = memcmp(a->ptr, b->ptr, min(a->size, b->size));
	return (result != 0) ? result :
		(a->size < b->size) ? -1 : (a->size > b->size) ? 1 : 0;
}
877

878 879 880 881 882 883 884
int git_buf_splice(
	git_buf *buf,
	size_t where,
	size_t nb_to_remove,
	const char *data,
	size_t nb_to_insert)
{
885 886
	char *splice_loc;
	size_t new_size, alloc_size;
887

888 889 890
	assert(buf && where <= buf->size && nb_to_remove <= buf->size - where);

	splice_loc = buf->ptr + where;
891 892 893 894

	/* Ported from git.git
	 * https://github.com/git/git/blob/16eed7c/strbuf.c#L159-176
	 */
895 896
	GIT_ERROR_CHECK_ALLOC_ADD(&new_size, (buf->size - nb_to_remove), nb_to_insert);
	GIT_ERROR_CHECK_ALLOC_ADD(&alloc_size, new_size, 1);
897
	ENSURE_SIZE(buf, alloc_size);
898

899 900 901
	memmove(splice_loc + nb_to_insert,
		splice_loc + nb_to_remove,
		buf->size - where - nb_to_remove);
902

903
	memcpy(splice_loc, data, nb_to_insert);
904

905
	buf->size = new_size;
906 907 908
	buf->ptr[buf->size] = '\0';
	return 0;
}
909

910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952
/* Quote per http://marc.info/?l=git&m=112927316408690&w=2 */
int git_buf_quote(git_buf *buf)
{
	const char whitespace[] = { 'a', 'b', 't', 'n', 'v', 'f', 'r' };
	git_buf quoted = GIT_BUF_INIT;
	size_t i = 0;
	bool quote = false;
	int error = 0;

	/* walk to the first char that needs quoting */
	if (buf->size && buf->ptr[0] == '!')
		quote = true;

	for (i = 0; !quote && i < buf->size; i++) {
		if (buf->ptr[i] == '"' || buf->ptr[i] == '\\' ||
			buf->ptr[i] < ' ' || buf->ptr[i] > '~') {
			quote = true;
			break;
		}
	}

	if (!quote)
		goto done;

	git_buf_putc(&quoted, '"');
	git_buf_put(&quoted, buf->ptr, i);

	for (; i < buf->size; i++) {
		/* whitespace - use the map above, which is ordered by ascii value */
		if (buf->ptr[i] >= '\a' && buf->ptr[i] <= '\r') {
			git_buf_putc(&quoted, '\\');
			git_buf_putc(&quoted, whitespace[buf->ptr[i] - '\a']);
		}

		/* double quote and backslash must be escaped */
		else if (buf->ptr[i] == '"' || buf->ptr[i] == '\\') {
			git_buf_putc(&quoted, '\\');
			git_buf_putc(&quoted, buf->ptr[i]);
		}

		/* escape anything unprintable as octal */
		else if (buf->ptr[i] != ' ' &&
				(buf->ptr[i] < '!' || buf->ptr[i] > '~')) {
953
			git_buf_printf(&quoted, "\\%03o", (unsigned char)buf->ptr[i]);
954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971
		}

		/* yay, printable! */
		else {
			git_buf_putc(&quoted, buf->ptr[i]);
		}
	}

	git_buf_putc(&quoted, '"');

	if (git_buf_oom(&quoted)) {
		error = -1;
		goto done;
	}

	git_buf_swap(&quoted, buf);

done:
972
	git_buf_dispose(&quoted);
973 974 975
	return error;
}

976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010
/* Unquote per http://marc.info/?l=git&m=112927316408690&w=2 */
int git_buf_unquote(git_buf *buf)
{
	size_t i, j;
	char ch;

	git_buf_rtrim(buf);

	if (buf->size < 2 || buf->ptr[0] != '"' || buf->ptr[buf->size-1] != '"')
		goto invalid;

	for (i = 0, j = 1; j < buf->size-1; i++, j++) {
		ch = buf->ptr[j];

		if (ch == '\\') {
			if (j == buf->size-2)
				goto invalid;

			ch = buf->ptr[++j];

			switch (ch) {
			/* \" or \\ simply copy the char in */
			case '"': case '\\':
				break;

			/* add the appropriate escaped char */
			case 'a': ch = '\a'; break;
			case 'b': ch = '\b'; break;
			case 'f': ch = '\f'; break;
			case 'n': ch = '\n'; break;
			case 'r': ch = '\r'; break;
			case 't': ch = '\t'; break;
			case 'v': ch = '\v'; break;

			/* \xyz digits convert to the char*/
1011
			case '0': case '1': case '2': case '3':
1012
				if (j == buf->size-3) {
1013
					git_error_set(GIT_ERROR_INVALID,
1014
						"truncated quoted character \\%c", ch);
1015 1016 1017 1018 1019
					return -1;
				}

				if (buf->ptr[j+1] < '0' || buf->ptr[j+1] > '7' ||
					buf->ptr[j+2] < '0' || buf->ptr[j+2] > '7') {
1020
					git_error_set(GIT_ERROR_INVALID,
1021
						"truncated quoted character \\%c%c%c",
1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032
						buf->ptr[j], buf->ptr[j+1], buf->ptr[j+2]);
					return -1;
				}

				ch = ((buf->ptr[j] - '0') << 6) |
					((buf->ptr[j+1] - '0') << 3) |
					(buf->ptr[j+2] - '0');
				j += 2;
				break;

			default:
1033
				git_error_set(GIT_ERROR_INVALID, "invalid quoted character \\%c", ch);
1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046
				return -1;
			}
		}

		buf->ptr[i] = ch;
	}

	buf->ptr[i] = '\0';
	buf->size = i;

	return 0;

invalid:
1047
	git_error_set(GIT_ERROR_INVALID, "invalid quoted line");
1048 1049
	return -1;
}