Merge branch 'ew/empty-merge-with-dirty-index-maint' into ew/empty-merge-with-dirty-index

* ew/empty-merge-with-dirty-index-maint:
merge-recursive: avoid incorporating uncommitted changes in a merge
move index_has_changes() from builtin/am.c to merge.c for reuse
t6044: recursive can silently incorporate dirty changes in a merge

diff --git a/builtin/am.c b/builtin/am.c
index 3d98e52085711abc6fa5ff9fd16d2828156df375..a02d5186cb9fabe4472ab1022fe00ec89349f5af 100644 (file)
--- a/builtin/am.c
+++ b/builtin/am.c
@@ -1142,43 +1142,6 @@ static void refresh_and_write_cache(void)
                die(_("unable to write index file"));
 }
 
-/**
- * Returns 1 if the index differs from HEAD, 0 otherwise. When on an unborn
- * branch, returns 1 if there are entries in the index, 0 otherwise. If an
- * strbuf is provided, the space-separated list of files that differ will be
- * appended to it.
- */
-static int index_has_changes(struct strbuf *sb)
-{
-       struct object_id head;
-       int i;
-
-       if (!get_oid_tree("HEAD", &head)) {
-               struct diff_options opt;
-
-               diff_setup(&opt);
-               opt.flags.exit_with_status = 1;
-               if (!sb)
-                       opt.flags.quick = 1;
-               do_diff_cache(&head, &opt);
-               diffcore_std(&opt);
-               for (i = 0; sb && i < diff_queued_diff.nr; i++) {
-                       if (i)
-                               strbuf_addch(sb, ' ');
-                       strbuf_addstr(sb, diff_queued_diff.queue[i]->two->path);
-               }
-               diff_flush(&opt);
-               return opt.flags.has_changes != 0;
-       } else {
-               for (i = 0; sb && i < active_nr; i++) {
-                       if (i)
-                               strbuf_addch(sb, ' ');
-                       strbuf_addstr(sb, active_cache[i]->name);
-               }
-               return !!active_nr;
-       }
-}
-
 /**
  * Dies with a user-friendly message on how to proceed after resolving the
  * problem. This message can be overridden with state->resolvemsg.

diff --git a/cache.h b/cache.h
index a2ec8c0b55422f2b95a30d140cb2bfdf15f0721d..d8b975a5715e8a5ec7c32e176958725cba61d67a 100644 (file)
--- a/cache.h
+++ b/cache.h
@@ -644,6 +644,15 @@ extern int write_locked_index(struct index_state *, struct lock_file *lock, unsi
 extern int discard_index(struct index_state *);
 extern void move_index_extensions(struct index_state *dst, struct index_state *src);
 extern int unmerged_index(const struct index_state *);
+
+/**
+ * Returns 1 if the index differs from HEAD, 0 otherwise. When on an unborn
+ * branch, returns 1 if there are entries in the index, 0 otherwise. If an
+ * strbuf is provided, the space-separated list of files that differ will be
+ * appended to it.
+ */
+extern int index_has_changes(struct strbuf *sb);
+
 extern int verify_path(const char *path);
 extern int strcmp_offset(const char *s1, const char *s2, size_t *first_change);
 extern int index_dir_exists(struct index_state *istate, const char *name, int namelen);

diff --git a/merge-recursive.c b/merge-recursive.c
index 2ecf495cc2a4a6d4544b92db1d2a8c3c0cc36f87..780f81a8bd3a729502cf2211a63135e4fba5d6cf 100644 (file)
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -1952,6 +1952,13 @@ int merge_trees(struct merge_options *o,
        }
 
        if (oid_eq(&common->object.oid, &merge->object.oid)) {
+               struct strbuf sb = STRBUF_INIT;
+
+               if (index_has_changes(&sb)) {
+                       err(o, _("Dirty index: cannot merge (dirty: %s)"),
+                           sb.buf);
+                       return 0;
+               }
                output(o, 0, _("Already up to date!"));
                *result = head;
                return 1;

diff --git a/merge.c b/merge.c
index e5d796c9f2d110bdcd378b361fe2052ac1dcc266..195b5787005ee8f63bc10845f6d788aa4730a61b 100644 (file)
--- a/merge.c
+++ b/merge.c
@@ -1,4 +1,6 @@
 #include "cache.h"
+#include "diff.h"
+#include "diffcore.h"
 #include "lockfile.h"
 #include "commit.h"
 #include "run-command.h"
@@ -15,6 +17,37 @@ static const char *merge_argument(struct commit *commit)
                return EMPTY_TREE_SHA1_HEX;
 }
 
+int index_has_changes(struct strbuf *sb)
+{
+       struct object_id head;
+       int i;
+
+       if (!get_oid_tree("HEAD", &head)) {
+               struct diff_options opt;
+
+               diff_setup(&opt);
+               opt.flags.exit_with_status = 1;
+               if (!sb)
+                       opt.flags.quick = 1;
+               do_diff_cache(&head, &opt);
+               diffcore_std(&opt);
+               for (i = 0; sb && i < diff_queued_diff.nr; i++) {
+                       if (i)
+                               strbuf_addch(sb, ' ');
+                       strbuf_addstr(sb, diff_queued_diff.queue[i]->two->path);
+               }
+               diff_flush(&opt);
+               return opt.flags.has_changes != 0;
+       } else {
+               for (i = 0; sb && i < active_nr; i++) {
+                       if (i)
+                               strbuf_addch(sb, ' ');
+                       strbuf_addstr(sb, active_cache[i]->name);
+               }
+               return !!active_nr;
+       }
+}
+
 int try_merge_command(const char *strategy, size_t xopts_nr,
                      const char **xopts, struct commit_list *common,
                      const char *head_arg, struct commit_list *remotes)

diff --git a/t/t6044-merge-unrelated-index-changes.sh b/t/t6044-merge-unrelated-index-changes.sh
index 01023486c5363da00c9e381fcf1e7d5479c348ae..23b86fb9778980ab813d5e252065ebe34fe4736d 100755 (executable)
--- a/t/t6044-merge-unrelated-index-changes.sh
+++ b/t/t6044-merge-unrelated-index-changes.sh
@@ -6,18 +6,21 @@ test_description="merges with unrelated index changes"
 
 # Testcase for some simple merges
 #   A
-#   o-----o B
+#   o-------o B
 #    \
-#     \---o C
+#     \-----o C
 #      \
-#       \-o D
+#       \---o D
 #        \
-#         o E
+#         \-o E
+#          \
+#           o F
 #   Commit A: some file a
 #   Commit B: adds file b, modifies end of a
 #   Commit C: adds file c
 #   Commit D: adds file d, modifies beginning of a
 #   Commit E: renames a->subdir/a, adds subdir/e
+#   Commit F: empty commit
 
 test_expect_success 'setup trivial merges' '
        test_seq 1 10 >a &&
@@ -29,6 +32,7 @@ test_expect_success 'setup trivial merges' '
        git branch C &&
        git branch D &&
        git branch E &&
+       git branch F &&
 
        git checkout B &&
        echo b >b &&
@@ -52,7 +56,10 @@ test_expect_success 'setup trivial merges' '
        git mv a subdir/a &&
        echo e >subdir/e &&
        git add subdir &&
-       test_tick && git commit -m E
+       test_tick && git commit -m E &&
+
+       git checkout F &&
+       test_tick && git commit --allow-empty -m F
 '
 
 test_expect_success 'ff update' '
@@ -105,6 +112,15 @@ test_expect_success 'recursive' '
        test_must_fail git merge -s recursive C^0
 '
 
+test_expect_success 'recursive, when merge branch matches merge base' '
+       git reset --hard &&
+       git checkout B^0 &&
+
+       touch random_file && git add random_file &&
+
+       test_must_fail git merge -s recursive F^0
+'
+
 test_expect_success 'octopus, unrelated file touched' '
        git reset --hard &&
        git checkout B^0 &&