attr: honor ignorecase in attribute matching

`.gitattributes` is case-insensitive when `core.ignorecase=true`.

Author: ethomson

src/libgit2/attr_file.c

@@ -347,7 +347,7 @@ int git_attr_file__parse_buffer(
 {
 	const char *scan = data, *context = NULL;
 	git_attr_rule *rule = NULL;
-	int error = 0;
+	int ignorecase = 0, error = 0;
 
 	/* If subdir file path, convert context for file paths */
 	if (attrs->entry && git_fs_path_root(attrs->entry->path) < 0 &&
@@ -379,6 +379,13 @@ int git_attr_file__parse_buffer(
 			continue;
 		}
 
+		if (repo &&
+		    (error = git_repository__configmap_lookup(&ignorecase, repo, GIT_CONFIGMAP_IGNORECASE)) < 0)
+			goto out;
+
+		if (ignorecase)
+			rule->match.flags |= GIT_ATTR_FNMATCH_ICASE;
+
 		if (rule->match.flags & GIT_ATTR_FNMATCH_MACRO) {
 			/* TODO: warning if macro found in file below repo root */
 			if (!allow_macros)
@@ -482,7 +489,7 @@ bool git_attr_fnmatch__match(
 	 */
 	if (match->containing_dir) {
 		if (match->flags & GIT_ATTR_FNMATCH_ICASE) {
-			if (git__strncasecmp(path->path, match->containing_dir, match->containing_dir_length))
+			if (git__prefixcmp_icase(path->path, match->containing_dir))
 				return 0;
 		} else {
 			if (git__prefixcmp(path->path, match->containing_dir))

tests/libgit2/filter/query.c

@@ -53,6 +53,18 @@ void test_filter_query__filters(void)
 	cl_assert_equal_i(1, filter_for("id.binident", "ident"));
 }
 
+void test_filter_query__filters_ignorecase(void)
+{
+	if (!cl_repo_get_bool(g_repo, "core.ignorecase"))
+		cl_skip();
+
+	cl_assert_equal_i(1, filter_for("TEXT.TXT", "crlf"));
+	cl_assert_equal_i(0, filter_for("Binary.bin", "crlf"));
+
+	cl_assert_equal_i(1, filter_for("id.Ident", "crlf"));
+	cl_assert_equal_i(1, filter_for("ID.IdEnT", "ident"));
+}
+
 void test_filter_query__autocrlf_true_implies_crlf(void)
 {
 	cl_repo_set_bool(g_repo, "core.autocrlf", true);