[PATCH v5 2/3] merge-recursive: option to disable renames

["Felipe Gonçalves Assis" <felipeg.assis@gmail.com>]

The recursive strategy turns on rename detection by default. Add a
strategy option to disable rename detection even for exact renames.

Signed-off-by: Felipe Gonçalves Assis <felipegassis@gmail.com>
---

Added tests.

For consistent naming, I renamed and slightly edited the test of whitespace
options:
t/t3032-merge-recursive-options.sh -> t/t3032-merge-recursive-space-options.sh

 Documentation/merge-strategies.txt                   |  6 ++++++
 merge-recursive.c                                    |  7 +++++++
 merge-recursive.h                                    |  1 +
 ...ons.sh => t3032-merge-recursive-space-options.sh} |  2 +-
 ...ld.sh => t3034-merge-recursive-rename-options.sh} | 20 +++++++++++++++++++-
 5 files changed, 34 insertions(+), 2 deletions(-)
 rename t/{t3032-merge-recursive-options.sh => t3032-merge-recursive-space-options.sh} (99%)
 rename t/{t3034-merge-recursive-rename-threshold.sh => t3034-merge-recursive-rename-options.sh} (83%)

diff --git a/Documentation/merge-strategies.txt b/Documentation/merge-strategies.txt
index 7bbd19b..1a5e197 100644
--- a/Documentation/merge-strategies.txt
+++ b/Documentation/merge-strategies.txt
@@ -81,8 +81,14 @@ no-renormalize;;
 	Disables the `renormalize` option.  This overrides the
 	`merge.renormalize` configuration variable.
 
+no-renames;;
+	Turn off rename detection.
+	See also linkgit:git-diff[1] `--no-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`.
 
 subtree[=<path>];;
diff --git a/merge-recursive.c b/merge-recursive.c
index 8eabde2..6dd0a11 100644
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -482,6 +482,9 @@ static struct string_list *get_renames(struct merge_options *o,
 	struct diff_options opts;
 
 	renames = xcalloc(1, sizeof(struct string_list));
+	if (!o->detect_rename)
+		return renames;
+
 	diff_setup(&opts);
 	DIFF_OPT_SET(&opts, RECURSIVE);
 	DIFF_OPT_CLR(&opts, RENAME_EMPTY);
@@ -2039,6 +2042,7 @@ void init_merge_options(struct merge_options *o)
 	o->diff_rename_limit = -1;
 	o->merge_rename_limit = -1;
 	o->renormalize = 0;
+	o->detect_rename = 1;
 	merge_recursive_config(o);
 	if (getenv("GIT_MERGE_VERBOSITY"))
 		o->verbosity =
@@ -2088,9 +2092,12 @@ 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 (!strcmp(s, "no-renames"))
+		o->detect_rename = 0;
 	else if (skip_prefix(s, "rename-threshold=", &arg)) {
 		if ((o->rename_score = parse_rename_score(&arg)) == -1 || *arg != 0)
 			return -1;
+		o->detect_rename = 1;
 	}
 	else
 		return -1;
diff --git a/merge-recursive.h b/merge-recursive.h
index 9e090a3..52f0201 100644
--- a/merge-recursive.h
+++ b/merge-recursive.h
@@ -17,6 +17,7 @@ struct merge_options {
 	unsigned renormalize : 1;
 	long xdl_opts;
 	int verbosity;
+	int detect_rename;
 	int diff_rename_limit;
 	int merge_rename_limit;
 	int rename_score;
diff --git a/t/t3032-merge-recursive-options.sh b/t/t3032-merge-recursive-space-options.sh
similarity index 99%
rename from t/t3032-merge-recursive-options.sh
rename to t/t3032-merge-recursive-space-options.sh
index 4029c9c..b56180e 100755
--- a/t/t3032-merge-recursive-options.sh
+++ b/t/t3032-merge-recursive-space-options.sh
@@ -1,6 +1,6 @@
 #!/bin/sh
 
-test_description='merge-recursive options
+test_description='merge-recursive space options
 
 * [master] Clarify
  ! [remote] Remove cruft
diff --git a/t/t3034-merge-recursive-rename-threshold.sh b/t/t3034-merge-recursive-rename-options.sh
similarity index 83%
rename from t/t3034-merge-recursive-rename-threshold.sh
rename to t/t3034-merge-recursive-rename-options.sh
index f0b3f44..2f10fa7 100755
--- a/t/t3034-merge-recursive-rename-threshold.sh
+++ b/t/t3034-merge-recursive-rename-options.sh
@@ -1,6 +1,6 @@
 #!/bin/sh
 
-test_description='merge-recursive rename threshold option
+test_description='merge-recursive rename options
 
 Test rename detection by examining rename/delete conflicts.
 
@@ -137,10 +137,28 @@ test_expect_success 'rename threshold is truncated' '
 	check_find_renames_100
 '
 
+test_expect_success 'disabled rename detection' '
+	git read-tree --reset -u HEAD &&
+	git merge-recursive --no-renames HEAD^ -- HEAD master &&
+	check_no_renames
+'
+
 test_expect_success 'last wins in --rename-threshold=<m> --rename-threshold=<n>' '
 	git read-tree --reset -u HEAD &&
 	test_must_fail git merge-recursive --rename-threshold=25 --rename-threshold=75 HEAD^ -- HEAD master &&
 	check_find_renames_75
 '
 
+test_expect_success 'last wins in --no-renames --rename-threshold=<n>' '
+	git read-tree --reset -u HEAD &&
+	test_must_fail git merge-recursive --no-renames --rename-threshold=25 HEAD^ -- HEAD master &&
+	check_find_renames_25
+'
+
+test_expect_success 'last wins in --rename-threshold=<n> --no-renames' '
+	git read-tree --reset -u HEAD &&
+	git merge-recursive --rename-threshold=25 --no-renames HEAD^ -- HEAD master &&
+	check_no_renames
+'
+
 test_done
-- 
2.7.1.342.gf5bb636