merge-recursive: more consistent interface

Add strategy option find-renames, following git-diff interface. This
makes the option rename-threshold redundant.

Signed-off-by: Felipe Gonçalves Assis <felipegassis@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/merge-strategies.txt

@@ -85,11 +85,13 @@ no-renames;;
 	Turn off rename detection.
 	See also linkgit:git-diff[1] `--no-renames`.
 
+find-renames[=<n>];;
+	Turn on rename detection, optionally setting the the similarity
+	threshold. This is the default.
+	See also linkgit:git-diff[1] `--find-renames`.
+
 rename-threshold=<n>;;
-	Controls the similarity threshold used for rename detection.
-	Re-enables rename detection if disabled by a preceding
-	`no-renames`.
-	See also linkgit:git-diff[1] `-M`.
+	Deprecated synonym for `find-renames=<n>`.
 
 subtree[=<path>];;
 	This option is a more advanced form of 'subtree' strategy, where

merge-recursive.c

@@ -2094,7 +2094,10 @@ int parse_merge_opt(struct merge_options *o, const char *s)
 		o->renormalize = 0;
 	else if (!strcmp(s, "no-renames"))
 		o->detect_rename = 0;
-	else if (skip_prefix(s, "rename-threshold=", &arg)) {
+	else if (!strcmp(s, "find-renames"))
+		o->detect_rename = 1;
+	else if (skip_prefix(s, "find-renames=", &arg) ||
+		 skip_prefix(s, "rename-threshold=", &arg)) {
 		if ((o->rename_score = parse_rename_score(&arg)) == -1 || *arg != 0)
 			return -1;
 		o->detect_rename = 1;