convert some config callbacks to parse_config_key

These callers can drop some inline pointer arithmetic and
magic offset constants, making them more readable and less
error-prone (those constants had to match the lengths of
strings, but there is no automatic verification of that
fact).

The "ep" pointer (presumably for "end pointer"), which
points to the final key segment of the config variable, is
given the more standard name "key" to describe its function
rather than its derivation.

Signed-off-by: Jeff King <peff@peff.net>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 5 insertions, 9 deletions

diff --git a/ll-merge.c b/ll-merge.c
index acea33b..fb61ea6 100644
--- a/ll-merge.c
+++ b/ll-merge.c
@@ -222,7 +222,7 @@ static const char *default_ll_merge;
 static int read_merge_config(const char *var, const char *value, void *cb)
 {
 	struct ll_merge_driver *fn;
-	const char *ep, *name;
+	const char *key, *name;
 	int namelen;
 
 	if (!strcmp(var, "merge.default")) {
@@ -236,15 +236,13 @@ static int read_merge_config(const char *var, const char *value, void *cb)
 	 * especially, we do not want to look at variables such as
 	 * "merge.summary", "merge.tool", and "merge.verbosity".
 	 */
-	if (prefixcmp(var, "merge.") || (ep = strrchr(var, '.')) == var + 5)
+	if (parse_config_key(var, "merge", &name, &namelen, &key) < 0 || !name)
 		return 0;
 
 	/*
 	 * Find existing one as we might be processing merge.<name>.var2
 	 * after seeing merge.<name>.var1.
 	 */
-	name = var + 6;
-	namelen = ep - name;
 	for (fn = ll_user_merge; fn; fn = fn->next)
 		if (!strncmp(fn->name, name, namelen) && !fn->name[namelen])
 			break;
@@ -256,16 +254,14 @@ static int read_merge_config(const char *var, const char *value, void *cb)
 		ll_user_merge_tail = &(fn->next);
 	}
 
-	ep++;
-
-	if (!strcmp("name", ep)) {
+	if (!strcmp("name", key)) {
 		if (!value)
 			return error("%s: lacks value", var);
 		fn->description = xstrdup(value);
 		return 0;
 	}
 
-	if (!strcmp("driver", ep)) {
+	if (!strcmp("driver", key)) {
 		if (!value)
 			return error("%s: lacks value", var);
 		/*
@@ -289,7 +285,7 @@ static int read_merge_config(const char *var, const char *value, void *cb)
 		return 0;
 	}
 
-	if (!strcmp("recursive", ep)) {
+	if (!strcmp("recursive", key)) {
 		if (!value)
 			return error("%s: lacks value", var);
 		fn->recursive = xstrdup(value);