diff-merges: refactor opt settings into separate functions

To prepare introduction of new options some of which will be synonyms
to existing options, let every option handling code just call
corresponding function.

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

diff-merges.c

@@ -10,12 +10,43 @@ static void suppress(struct rev_info *revs)
 	revs->dense_combined_merges = 0;
 }
 
+static void set_separate(struct rev_info *revs)
+{
+	suppress(revs);
+	revs->separate_merges = 1;
+}
+
+static void set_m(struct rev_info *revs)
+{
+	/*
+	 * To "diff-index", "-m" means "match missing", and to the "log"
+	 * family of commands, it means "show full diff for merges". Set
+	 * both fields appropriately.
+	 */
+	set_separate(revs);
+	revs->match_missing = 1;
+}
+
+static void set_combined(struct rev_info *revs)
+{
+	revs->combine_merges = 1;
+	revs->dense_combined_merges = 0;
+}
+
 static void set_dense_combined(struct rev_info *revs)
 {
 	revs->combine_merges = 1;
 	revs->dense_combined_merges = 1;
 }
 
+static void set_diff_merges(struct rev_info *revs, const char *optarg)
+{
+	if (!strcmp(optarg, "off")) {
+		suppress(revs);
+	} else {
+		die(_("unknown value for --diff-merges: %s"), optarg);
+	}
+}
 
 /*
  * Public functions. They are in the order they are called.
@@ -27,31 +58,19 @@ int diff_merges_parse_opts(struct rev_info *revs, const char **argv)
 	const char *optarg;
 	const char *arg = argv[0];
 
-	if (!strcmp(arg, "-m")) {
-		suppress(revs);
-		/*
-		 * To "diff-index", "-m" means "match missing", and to the "log"
-		 * family of commands, it means "show full diff for merges". Set
-		 * both fields appropriately.
-		 */
-		revs->separate_merges = 1;
-		revs->match_missing = 1;
-	} else if (!strcmp(arg, "-c")) {
-		revs->dense_combined_merges = 0;
-		revs->combine_merges = 1;
-	} else if (!strcmp(arg, "--cc")) {
+	if (!strcmp(arg, "-m"))
+		set_m(revs);
+	else if (!strcmp(arg, "-c"))
+		set_combined(revs);
+	else if (!strcmp(arg, "--cc"))
 		set_dense_combined(revs);
-	} else if (!strcmp(arg, "--no-diff-merges")) {
+	else if (!strcmp(arg, "--no-diff-merges"))
 		suppress(revs);
-	} else if (!strcmp(arg, "--combined-all-paths")) {
+	else if (!strcmp(arg, "--combined-all-paths"))
 		revs->combined_all_paths = 1;
-	} else if ((argcount = parse_long_opt("diff-merges", argv, &optarg))) {
-		if (!strcmp(optarg, "off")) {
-			suppress(revs);
-		} else {
-			die(_("unknown value for --diff-merges: %s"), optarg);
-		}
-	} else
+	else if ((argcount = parse_long_opt("diff-merges", argv, &optarg)))
+		set_diff_merges(revs, optarg);
+	else
 		return 0;
 
 	revs->explicit_diff_merges = 1;