[PATCHv2 2/2] diff: add synonyms for -M, -C, -B

[Kevin Ballard <kevin@sb.org>]

Add new long-form options --detect-renames[=<n>], --detect-copies[=<n>],
and --break-rewrites[=[<n>][/<m>]] as synonyms for the -M, -C, and -B
options (respectively).

Signed-off-by: Kevin Ballard <kevin@sb.org>
---
After thinking about it, I decided that --rename-threshold doesn't make sense
as a long-form option because it doesn't make its meaning obvious when you
don't specify the optional argument. I also figured it doesn't need to match
exactly with the rename-threshold merge strategy option as merge-recursive
already turns on rename detection and the option just controls the threshold.
However, the option to git-diff actually turns on rename detection instead of
just controlling the threshold.

 Documentation/diff-options.txt |    3 +++
 diff.c                         |   25 ++++++++++++++++++++++---
 2 files changed, 25 insertions(+), 3 deletions(-)

diff --git a/Documentation/diff-options.txt b/Documentation/diff-options.txt
index f77a0f8..a511529 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/diff.c b/diff.c
index d862234..d8fcf06 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)
@@ -3366,6 +3369,22 @@ 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 */
 
-- 
1.7.3.72.g8af0.dirty