Wrap up ignore API and add tests

This fills out the ignore API and adds tests.

include/git2/ignore.h

+/*
+ * Copyright (C) 2012 the libgit2 contributors
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_ignore_h__
+#define INCLUDE_git_ignore_h__
+
+#include "common.h"
+#include "types.h"
+
+GIT_BEGIN_DECL
+
+/**
+ * Add ignore rules for a repository.
+ *
+ * Excludesfile rules (i.e. .gitignore rules) are generally read from
+ * .gitignore files in the repository tree or from a shared system file
+ * only if a "core.excludesfile" config value is set.  The library also
+ * keeps a set of per-repository internal ignores that can be configured
+ * in-memory and will not persist.  This function allows you to add to
+ * that internal rules list.
+ *
+ * Example usage:
+ *
+ *     error = git_ignore_add(myrepo, "*.c\ndir/\nFile with space\n");
+ *
+ * This would add three rules to the ignores.
+ *
+ * @param repo The repository to add ignore rules to.
+ * @param rules Text of rules, a la the contents of a .gitignore file.
+ *              It is okay to have multiple rules in the text; if so,
+ *              each rule should be terminated with a newline.
+ * @return 0 on success
+ */
+GIT_EXTERN(int) git_ignore_add_rule(
+	git_repository *repo,
+	const char *rules);
+
+/**
+ * Clear ignore rules that were explicitly added.
+ *
+ * Clears the internal ignore rules that have been set up.  This will not
+ * turn off the rules in .gitignore files that actually exist in the
+ * filesystem.
+ *
+ * @param repo The repository to remove ignore rules from.
+ * @return 0 on success
+ */
+GIT_EXTERN(int) git_ignore_clear_internal_rules(
+	git_repository *repo);
+
+/**
+ * Test if the ignore rules apply to a given path.
+ *
+ * This function simply checks the ignore rules to see if they would apply
+ * to the given file.  This indicates if the file would be ignored regardless
+ * of whether the file is already in the index or commited to the repository.
+ *
+ * @param ignored boolean returning 0 if the file is not ignored, 1 if it is
+ * @param repo a repository object
+ * @param path the file to check ignores for, relative to the repo's workdir.
+ * @return 0 if ignore rules could be processed for the file (regardless
+ *         of whether it exists or not), or an error < 0 if they could not.
+ */
+GIT_EXTERN(int) git_ignore_path_is_ignored(
+	int *ignored,
+	git_repository *repo,
+	const char *path);
+
+GIT_END_DECL
+
+#endif

src/ignore.c

@@ -235,3 +235,20 @@ int git_ignore_clear_internal_rules(
 
 	return error;
 }
+
+int git_ignore_path_is_ignored(
+	int *ignored,
+	git_repository *repo,
+	const char *path)
+{
+	int error;
+	git_ignores ignores;
+
+	if (git_ignore__for_path(repo, path, &ignores) < 0)
+		return -1;
+
+	error = git_ignore__lookup(&ignores, path, ignored);
+	git_ignore__free(&ignores);
+	return error;
+}
+

src/status.c

@@ -243,14 +243,6 @@ int git_status_should_ignore(
 	git_repository *repo,
 	const char *path)
 {
-	int error;
-	git_ignores ignores;
-
-	if (git_ignore__for_path(repo, path, &ignores) < 0)
-		return -1;
-
-	error = git_ignore__lookup(&ignores, path, ignored);
-	git_ignore__free(&ignores);
-	return error;
+	return git_ignore_path_is_ignored(ignored, repo, path);
 }
 

tests-clar/status/ignore.c

@@ -139,9 +139,63 @@ void test_status_ignore__ignore_pattern_contains_space(void)
 	g_repo = cl_git_sandbox_init("empty_standard_repo");
 	cl_git_rewritefile("empty_standard_repo/.gitignore", "foo bar.txt\n");
 
+	cl_git_mkfile(
+		"empty_standard_repo/foo bar.txt", "I'm going to be ignored!");
+
+	cl_git_pass(git_status_file(&flags, g_repo, "foo bar.txt"));
+	cl_assert(flags == GIT_STATUS_IGNORED);
+
 	cl_git_pass(git_futils_mkdir_r("empty_standard_repo/foo", NULL, mode));
 	cl_git_mkfile("empty_standard_repo/foo/look-ma.txt", "I'm not going to be ignored!");
 
 	cl_git_pass(git_status_file(&flags, g_repo, "foo/look-ma.txt"));
 	cl_assert(flags == GIT_STATUS_WT_NEW);
 }
+
+void test_status_ignore__adding_internal_ignores(void)
+{
+	int ignored;
+
+	g_repo = cl_git_sandbox_init("empty_standard_repo");
+
+	cl_git_pass(git_status_should_ignore(&ignored, g_repo, "one.txt"));
+	cl_assert(!ignored);
+	cl_git_pass(git_status_should_ignore(&ignored, g_repo, "two.bar"));
+	cl_assert(!ignored);
+
+	cl_git_pass(git_ignore_add_rule(g_repo, "*.nomatch\n"));
+
+	cl_git_pass(git_status_should_ignore(&ignored, g_repo, "one.txt"));
+	cl_assert(!ignored);
+	cl_git_pass(git_status_should_ignore(&ignored, g_repo, "two.bar"));
+	cl_assert(!ignored);
+
+	cl_git_pass(git_ignore_add_rule(g_repo, "*.txt\n"));
+
+	cl_git_pass(git_status_should_ignore(&ignored, g_repo, "one.txt"));
+	cl_assert(ignored);
+	cl_git_pass(git_status_should_ignore(&ignored, g_repo, "two.bar"));
+	cl_assert(!ignored);
+
+	cl_git_pass(git_ignore_add_rule(g_repo, "*.bar\n"));
+
+	cl_git_pass(git_status_should_ignore(&ignored, g_repo, "one.txt"));
+	cl_assert(ignored);
+	cl_git_pass(git_status_should_ignore(&ignored, g_repo, "two.bar"));
+	cl_assert(ignored);
+
+	cl_git_pass(git_ignore_clear_internal_rules(g_repo));
+
+	cl_git_pass(git_status_should_ignore(&ignored, g_repo, "one.txt"));
+	cl_assert(!ignored);
+	cl_git_pass(git_status_should_ignore(&ignored, g_repo, "two.bar"));
+	cl_assert(!ignored);
+
+	cl_git_pass(git_ignore_add_rule(
+		g_repo, "multiple\n*.rules\n# comment line\n*.bar\n"));
+
+	cl_git_pass(git_status_should_ignore(&ignored, g_repo, "one.txt"));
+	cl_assert(!ignored);
+	cl_git_pass(git_status_should_ignore(&ignored, g_repo, "two.bar"));
+	cl_assert(ignored);
+}