[PATCH] builtin/log: honor log.decorate

["brian m. carlson" <sandals@crustytoothpaste.net>]

The recent change that introduced autodecorating of refs accidentally
broke the ability of users to set log.decorate = false to override it.
When the git_log_config was traversed a second time with an option other
than log.decorate, the decoration style would be set to the automatic
style, even if the user had already overridden it.  Only set the option
to its default value if we haven't set it already.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
---
 builtin/log.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/builtin/log.c b/builtin/log.c
index b3b10cc1e..304923836 100644
--- a/builtin/log.c
+++ b/builtin/log.c
@@ -34,7 +34,7 @@ static int default_abbrev_commit;
 static int default_show_root = 1;
 static int default_follow;
 static int default_show_signature;
-static int decoration_style;
+static int decoration_style = -1;
 static int decoration_given;
 static int use_mailmap_config;
 static const char *fmt_patch_subject_prefix = "PATCH";
@@ -410,7 +410,7 @@ static int git_log_config(const char *var, const char *value, void *cb)
 		if (decoration_style < 0)
 			decoration_style = 0; /* maybe warn? */
 		return 0;
-	} else {
+	} else if (decoration_style == -1) {
 		decoration_style = auto_decoration_style();
 	}
 	if (!strcmp(var, "log.showroot")) {