[PATCH/RFC] alias.c: Replace git_config with git_config_get_string

[Tanay Abhra <tanayabh@gmail.com>]

Original implementation uses a callback based approach which has some
deficiencies like a convoluted control flow and redundant variables.
Use git_config_get_string instead of git_config to take advantage of
the config hash-table.

Signed-off-by: Tanay Abhra <tanayabh@gmail.com>
---

**DOUBT**
This patch builds on top of patch series[1]. The first patch in the 
replace `git_config` series is [2], which passed all the tests.

But this patch falters at this test in t1300-repo-config.sh,

git config alias.checkconfig "-c foo.check=bar config foo.check" &&
		echo bar >expect &&
		git checkconfig >actual &&
		test_cmp expect actual

I hand tested this case and the outputs match. But I don't know why the tests
are failing.

In t1300-repo-config this test also fails,

#		git config alias.split-cmdline-fix 'echo "' &&
#		test_must_fail git split-cmdline-fix &&
#		echo foo > foo &&
#		git add foo &&
#		git commit -m 'initial commit' &&
#		git config branch.master.mergeoptions 'echo "' &&
#		test_must_fail git merge master

Can anybody help me with this one?
Thanks.

[1] http://thread.gmane.org/gmane.comp.version-control.git/251704
[2] http://thread.gmane.org/gmane.comp.version-control.git/251707

Cheers,
Tanay Abhra.

 alias.c | 27 ++++++++++-----------------
 1 file changed, 10 insertions(+), 17 deletions(-)

diff --git a/alias.c b/alias.c
index 5efc3d6..fffad73 100644
--- a/alias.c
+++ b/alias.c
@@ -1,24 +1,17 @@
 #include "cache.h"
 
-static const char *alias_key;
-static char *alias_val;
-
-static int alias_lookup_cb(const char *k, const char *v, void *cb)
-{
-	if (starts_with(k, "alias.") && !strcmp(k + 6, alias_key)) {
-		if (!v)
-			return config_error_nonbool(k);
-		alias_val = xstrdup(v);
-		return 0;
-	}
-	return 0;
-}
-
 char *alias_lookup(const char *alias)
 {
-	alias_key = alias;
-	alias_val = NULL;
-	git_config(alias_lookup_cb, NULL);
+	char *alias_key, *alias_val;
+	const char *v;
+	alias_key = xmalloc(7+strlen(alias));
+	strcpy(alias_key, "alias.");
+	strcat(alias_key, alias);
+	v = git_config_get_string(alias_key);
+	if (!v)
+		config_error_nonbool(alias_key);
+	alias_val = xstrdup(v);
+	free(alias_key);
 	return alias_val;
 }
 
-- 
1.9.0.GIT