attr: read core.attributesfile from git_default_core_config

This code calls git_config from a helper function to parse the config entry
it is interested in.  Calling git_config in this way may cause a problem if
the helper function can be called after a previous call to git_config by
another function since the second call to git_config may reset some
variable to the value in the config file which was previously overridden.

The above is not a problem in this case since the function passed to
git_config only parses one config entry and the variable it sets is not
assigned outside of the parsing function.  But a programmer who desires
all of the standard config options to be parsed may be tempted to modify
git_attr_config() so that it falls back to git_default_config() and then it
_would_ be vulnerable to the above described behavior.

So, move the call to git_config up into the top-level cmd_* function and
move the responsibility for parsing core.attributesfile into the main
config file parser.

Which is only the logical thing to do ;-)

Signed-off-by: Brandon Casey <drafnel@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

attr.c

@@ -20,8 +20,6 @@ static const char git_attr__unknown[] = "(builtin)unknown";
 #define ATTR__UNSET NULL
 #define ATTR__UNKNOWN git_attr__unknown
 
-static const char *attributes_file;
-
 /* This is a randomly chosen prime. */
 #define HASHSIZE 257
 
@@ -494,14 +492,6 @@ static int git_attr_system(void)
 	return !git_env_bool("GIT_ATTR_NOSYSTEM", 0);
 }
 
-static int git_attr_config(const char *var, const char *value, void *dummy)
-{
-	if (!strcmp(var, "core.attributesfile"))
-		return git_config_pathname(&attributes_file, var, value);
-
-	return 0;
-}
-
 static void bootstrap_attr_stack(void)
 {
 	if (!attr_stack) {
@@ -521,9 +511,8 @@ static void bootstrap_attr_stack(void)
 			}
 		}
 
-		git_config(git_attr_config, NULL);
+		if (git_attributes_file) {
-		if (attributes_file) {
+			elem = read_attr_from_file(git_attributes_file, 1);
-			elem = read_attr_from_file(attributes_file, 1);
 			if (elem) {
 				elem->origin = NULL;
 				elem->prev = attr_stack;

builtin/check-attr.c

@@ -92,6 +92,8 @@ int cmd_check_attr(int argc, const char **argv, const char *prefix)
 	struct git_attr_check *check;
 	int cnt, i, doubledash, filei;
 
+	git_config(git_default_config, NULL);
+
 	argc = parse_options(argc, argv, prefix, check_attr_options,
 			     check_attr_usage, PARSE_OPT_KEEP_DASHDASH);
 

cache.h

@@ -589,6 +589,7 @@ extern int warn_ambiguous_refs;
 extern int shared_repository;
 extern const char *apply_default_whitespace;
 extern const char *apply_default_ignorewhitespace;
+extern const char *git_attributes_file;
 extern int zlib_compression_level;
 extern int core_compression_level;
 extern int core_compression_seen;

config.c

@@ -491,6 +491,9 @@ static int git_default_core_config(const char *var, const char *value)
 		return 0;
 	}
 
+	if (!strcmp(var, "core.attributesfile"))
+		return git_config_pathname(&git_attributes_file, var, value);
+
 	if (!strcmp(var, "core.bare")) {
 		is_bare_repository_cfg = git_config_bool(var, value);
 		return 0;

environment.c

@@ -29,6 +29,7 @@ const char *git_log_output_encoding;
 int shared_repository = PERM_UMASK;
 const char *apply_default_whitespace;
 const char *apply_default_ignorewhitespace;
+const char *git_attributes_file;
 int zlib_compression_level = Z_BEST_SPEED;
 int core_compression_level;
 int core_compression_seen;