Merge branch 'kb/merge-recursive-rename-threshold'

* kb/merge-recursive-rename-threshold:
  diff: add synonyms for -M, -C, -B
  merge-recursive: option to specify rename threshold

Conflicts:
	Documentation/diff-options.txt
	Documentation/merge-strategies.txt

6 files changed, 41 insertions, 6 deletions

diff --git a/Documentation/diff-options.txt b/Documentation/diff-options.txt
index e954af0ad6..bfd0b571e2 100644
--- a/Documentation/diff-options.txt
+++ b/Documentation/diff-options.txt
@@ -207,6 +207,7 @@ endif::git-format-patch[]
 	digits can be specified with `--abbrev=<n>`.
 
 -B[<n>][/<m>]::
+--break-rewrites[=[<n>][/<m>]]::
 	Break complete rewrite changes into pairs of delete and
 	create. This serves two purposes:
 +
@@ -229,6 +230,7 @@ eligible for being picked up as a possible source of a rename to
 another file.
 
 -M[<n>]::
+--detect-renames[=<n>]::
 ifndef::git-log[]
 	Detect renames.
 endif::git-log[]
@@ -244,6 +246,7 @@ endif::git-log[]
 	hasn't changed.
 
 -C[<n>]::
+--detect-copies[=<n>]::
 	Detect copies as well as renames.  See also `--find-copies-harder`.
 	If `n` is specified, it has the same meaning as for `-M<n>`.
 
diff --git a/Documentation/merge-strategies.txt b/Documentation/merge-strategies.txt
index 9cf88e2bb5..595a3cf1a7 100644
--- a/Documentation/merge-strategies.txt
+++ b/Documentation/merge-strategies.txt
@@ -74,6 +74,10 @@ no-renormalize;;
 	Disables the `renormalize` option.  This overrides the
 	`merge.renormalize` configuration variable.
 
+rename-threshold=<n>;;
+	Controls the similarity threshold used for rename detection.
+	See also linkgit:git-diff[1] `-M`.
+
 subtree[=<path>];;
 	This option is a more advanced form of 'subtree' strategy, where
 	the strategy makes a guess on how two trees must be shifted to
diff --git a/diff.c b/diff.c
index ba57bfab17..d1c6b91982 100644
--- a/diff.c
+++ b/diff.c
@@ -3140,16 +3140,19 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
 		return stat_opt(options, av);
 
 	/* renames options */
-	else if (!prefixcmp(arg, "-B")) {
+	else if (!prefixcmp(arg, "-B") || !prefixcmp(arg, "--break-rewrites=") ||
+		 !strcmp(arg, "--break-rewrites")) {
 		if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
 			return -1;
 	}
-	else if (!prefixcmp(arg, "-M")) {
+	else if (!prefixcmp(arg, "-M") || !prefixcmp(arg, "--detect-renames=") ||
+		 !strcmp(arg, "--detect-renames")) {
 		if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
 			return -1;
 		options->detect_rename = DIFF_DETECT_RENAME;
 	}
-	else if (!prefixcmp(arg, "-C")) {
+	else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--detect-copies=") ||
+		 !strcmp(arg, "--detect-copies")) {
 		if (options->detect_rename == DIFF_DETECT_COPY)
 			DIFF_OPT_SET(options, FIND_COPIES_HARDER);
 		if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
@@ -3323,7 +3326,7 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
 	return 1;
 }
 
-static int parse_num(const char **cp_p)
+int parse_rename_score(const char **cp_p)
 {
 	unsigned long num, scale;
 	int ch, dot;
@@ -3366,10 +3369,26 @@ static int diff_scoreopt_parse(const char *opt)
 	if (*opt++ != '-')
 		return -1;
 	cmd = *opt++;
+	if (cmd == '-') {
+		/* convert the long-form arguments into short-form versions */
+		if (!prefixcmp(opt, "break-rewrites")) {
+			opt += strlen("break-rewrites");
+			if (*opt == 0 || *opt++ == '=')
+				cmd = 'B';
+		} else if (!prefixcmp(opt, "detect-copies")) {
+			opt += strlen("detect-copies");
+			if (*opt == 0 || *opt++ == '=')
+				cmd = 'C';
+		} else if (!prefixcmp(opt, "detect-renames")) {
+			opt += strlen("detect-renames");
+			if (*opt == 0 || *opt++ == '=')
+				cmd = 'M';
+		}
+	}
 	if (cmd != 'M' && cmd != 'C' && cmd != 'B')
 		return -1; /* that is not a -M, -C nor -B option */
 
-	opt1 = parse_num(&opt);
+	opt1 = parse_rename_score(&opt);
 	if (cmd != 'B')
 		opt2 = 0;
 	else {
@@ -3379,7 +3398,7 @@ static int diff_scoreopt_parse(const char *opt)
 			return -1; /* we expect -B80/99 or -B80 */
 		else {
 			opt++;
-			opt2 = parse_num(&opt);
+			opt2 = parse_rename_score(&opt);
 		}
 	}
 	if (*opt != 0)
diff --git a/diff.h b/diff.h
index 1fd44f5e47..0083d92438 100644
--- a/diff.h
+++ b/diff.h
@@ -315,4 +315,6 @@ extern size_t fill_textconv(struct userdiff_driver *driver,
 
 extern struct userdiff_driver *get_textconv(struct diff_filespec *one);
 
+extern int parse_rename_score(const char **cp_p);
+
 #endif /* DIFF_H */
diff --git a/merge-recursive.c b/merge-recursive.c
index 325a97bf31..875859f68e 100644
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -334,6 +334,7 @@ static struct string_list *get_renames(struct merge_options *o,
 	opts.rename_limit = o->merge_rename_limit >= 0 ? o->merge_rename_limit :
 			    o->diff_rename_limit >= 0 ? o->diff_rename_limit :
 			    500;
+	opts.rename_score = o->rename_score;
 	opts.warn_on_too_large_rename = 1;
 	opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 	if (diff_setup_done(&opts) < 0)
@@ -1576,6 +1577,11 @@ int parse_merge_opt(struct merge_options *o, const char *s)
 		o->renormalize = 1;
 	else if (!strcmp(s, "no-renormalize"))
 		o->renormalize = 0;
+	else if (!prefixcmp(s, "rename-threshold=")) {
+		const char *score = s + strlen("rename-threshold=");
+		if ((o->rename_score = parse_rename_score(&score)) == -1 || *score != 0)
+			return -1;
+	}
 	else
 		return -1;
 	return 0;
diff --git a/merge-recursive.h b/merge-recursive.h
index 2eb5d1aad5..c8135b0ec7 100644
--- a/merge-recursive.h
+++ b/merge-recursive.h
@@ -19,6 +19,7 @@ struct merge_options {
 	int verbosity;
 	int diff_rename_limit;
 	int merge_rename_limit;
+	int rename_score;
 	int call_depth;
 	struct strbuf obuf;
 	struct string_list current_file_set;