Merge branch 'jc/abbrev-autoscale-config' into maint

Recent update to the default abbreviation length that auto-scales
lacked documentation update, which has been corrected.

* jc/abbrev-autoscale-config:
  config.abbrev: document the new default that auto-scales

1 files changed, 10 insertions, 4 deletions

diff --git a/config.c b/config.c
index 2f1aef742e..0b9c1b62bb 100644
--- a/config.c
+++ b/config.c
@@ -836,10 +836,16 @@ static int git_default_core_config(const char *var, const char *value)
 	}
 
 	if (!strcmp(var, "core.abbrev")) {
-		int abbrev = git_config_int(var, value);
-		if (abbrev < minimum_abbrev || abbrev > 40)
-			return -1;
-		default_abbrev = abbrev;
+		if (!value)
+			return config_error_nonbool(var);
+		if (!strcasecmp(value, "auto"))
+			default_abbrev = -1;
+		else {
+			int abbrev = git_config_int(var, value);
+			if (abbrev < minimum_abbrev || abbrev > 40)
+				return error("abbrev length out of range: %d", abbrev);
+			default_abbrev = abbrev;
+		}
 		return 0;
 	}