Merge branch 'en/merge-recursive'

* en/merge-recursive:
  merge-recursive: tweak magic band-aid
  merge-recursive: When we detect we can skip an update, actually skip it
  t6022: New test checking for unnecessary updates of files in D/F conflicts
  t6022: New test checking for unnecessary updates of renamed+modified files

diff --git a/merge-recursive.c b/merge-recursive.c
index af131508ec7ffa3ac7b1b1b1cadfcda0040becf2..7c126735535f390b54c02920f1df58acaf34532e 100644 (file)
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -344,10 +344,11 @@ static void make_room_for_directories_of_df_conflicts(struct merge_options *o,
         * make room for the corresponding directory.  Such paths will
         * later be processed in process_df_entry() at the end.  If
         * the corresponding directory ends up being removed by the
-        * merge, then the file will be reinstated at that time;
-        * otherwise, if the file is not supposed to be removed by the
-        * merge, the contents of the file will be placed in another
-        * unique filename.
+        * merge, then the file will be reinstated at that time
+        * (albeit with a different timestamp!); otherwise, if the
+        * file is not supposed to be removed by the merge, the
+        * contents of the file will be placed in another unique
+        * filename.
         *
         * NOTE: This function relies on the fact that entries for a
         * D/F conflict will appear adjacent in the index, with the
@@ -358,6 +359,13 @@ static void make_room_for_directories_of_df_conflicts(struct merge_options *o,
        int last_len = 0;
        int i;
 
+       /*
+        * Do not do any of this crazyness during the recursive; we don't
+        * even write anything to the working tree!
+        */
+       if (o->call_depth)
+               return;
+
        for (i = 0; i < entries->nr; i++) {
                const char *path = entries->items[i].string;
                int len = strlen(path);
@@ -1260,9 +1268,13 @@ static int merge_content(struct merge_options *o,
        }
 
        if (mfi.clean && !df_conflict_remains &&
-           sha_eq(mfi.sha, a_sha) && mfi.mode == a.mode)
+           sha_eq(mfi.sha, a_sha) && mfi.mode == a.mode &&
+           !o->call_depth && !lstat(path, &st)) {
                output(o, 3, "Skipped %s (merged same as existing)", path);
-       else
+               add_cacheinfo(mfi.mode, mfi.sha, path,
+                             0 /*stage*/, 1 /*refresh*/, 0 /*options*/);
+               return mfi.clean;
+       } else
                output(o, 2, "Auto-merging %s", path);
 
        if (!mfi.clean) {

diff --git a/t/t6022-merge-rename.sh b/t/t6022-merge-rename.sh
index 1ed259d864b4ef4c8c7060fa5f22634a25c8e032..5f3b604fd99b22c73cfdebf0f1cf13539e1af3e4 100755 (executable)
--- a/t/t6022-merge-rename.sh
+++ b/t/t6022-merge-rename.sh
@@ -609,4 +609,67 @@ test_expect_success 'check handling of differently renamed file with D/F conflic
        ! test -f original
 '
 
+test_expect_success 'setup avoid unnecessary update, normal rename' '
+       git reset --hard &&
+       git checkout --orphan avoid-unnecessary-update-1 &&
+       git rm -rf . &&
+       git clean -fdqx &&
+
+       printf "1\n2\n3\n4\n5\n6\n7\n8\n9\n10\n" >original &&
+       git add -A &&
+       git commit -m "Common commmit" &&
+
+       git mv original rename &&
+       echo 11 >>rename &&
+       git add -u &&
+       git commit -m "Renamed and modified" &&
+
+       git checkout -b merge-branch-1 HEAD~1 &&
+       echo "random content" >random-file &&
+       git add -A &&
+       git commit -m "Random, unrelated changes"
+'
+
+test_expect_success 'avoid unnecessary update, normal rename' '
+       git checkout -q avoid-unnecessary-update-1^0 &&
+       test-chmtime =1000000000 rename &&
+       test-chmtime -v +0 rename >expect &&
+       git merge merge-branch-1 &&
+       test-chmtime -v +0 rename >actual &&
+       test_cmp expect actual # "rename" should have stayed intact
+'
+
+test_expect_success 'setup to test avoiding unnecessary update, with D/F conflict' '
+       git reset --hard &&
+       git checkout --orphan avoid-unnecessary-update-2 &&
+       git rm -rf . &&
+       git clean -fdqx &&
+
+       mkdir df &&
+       printf "1\n2\n3\n4\n5\n6\n7\n8\n9\n10\n" >df/file &&
+       git add -A &&
+       git commit -m "Common commmit" &&
+
+       git mv df/file temp &&
+       rm -rf df &&
+       git mv temp df &&
+       echo 11 >>df &&
+       git add -u &&
+       git commit -m "Renamed and modified" &&
+
+       git checkout -b merge-branch-2 HEAD~1 &&
+       >unrelated-change &&
+       git add unrelated-change &&
+       git commit -m "Only unrelated changes"
+'
+
+test_expect_failure 'avoid unnecessary update, with D/F conflict' '
+       git checkout -q avoid-unnecessary-update-2^0 &&
+       test-chmtime =1000000000 df &&
+       test-chmtime -v +0 df >expect &&
+       git merge merge-branch-2 &&
+       test-chmtime -v +0 df >actual &&
+       test_cmp expect actual # "df" should have stayed intact
+'
+
 test_done