diff-merges: rename diff_merges_default_to_enable() to match semantics

Rename diff_merges_default_to_enable() to
diff_merges_default_to_first_parent() to match its semantics.

Signed-off-by: Sergey Organov <sorganov@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/log.c

@@ -600,7 +600,7 @@ static void show_setup_revisions_tweak(struct rev_info *rev,
 				       struct setup_revision_opt *opt)
 {
 	if (rev->first_parent_only)
-		diff_merges_default_to_enable(rev);
+		diff_merges_default_to_first_parent(rev);
 	else
 		diff_merges_default_to_dense_combined(rev);
 	if (!rev->diffopt.output_format)
@@ -728,7 +728,7 @@ static void log_setup_revisions_tweak(struct rev_info *rev,
 		rev->diffopt.output_format = DIFF_FORMAT_PATCH;
 
 	if (rev->first_parent_only)
-		diff_merges_default_to_enable(rev);
+		diff_merges_default_to_first_parent(rev);
 }
 
 int cmd_log(int argc, const char **argv, const char *prefix)

diff-merges.c

@@ -56,7 +56,7 @@ void diff_merges_setup_revs(struct rev_info *revs)
 		die("--combined-all-paths makes no sense without -c or --cc");
 }
 
-void diff_merges_default_to_enable(struct rev_info *revs)
+void diff_merges_default_to_first_parent(struct rev_info *revs)
 {
 	if (revs->ignore_merges < 0)		/* No -m */
 		revs->ignore_merges = 0;

diff-merges.h

@@ -17,7 +17,7 @@ void diff_merges_setup_revs(struct rev_info *revs);
 
 void diff_merges_default_to_dense_combined(struct rev_info *revs);
 
-void diff_merges_default_to_enable(struct rev_info *revs);
+void diff_merges_default_to_first_parent(struct rev_info *revs);
 
 
 #endif