[PATCH] git mv: try harder to keep index entries intact
From: Johannes Schindelin <hidden>
Date: 2016-06-15 22:45:05
Subsystem:
the rest · Maintainer:
Linus Torvalds
Some filesystems change the ctime during a rename(), for technical reasons. Since this is the only change, the contents need not be rehashed. So just update the ctime after renaming the entry. This change requires rename_index_entry_at() to return the new position. As git-mv assumes that it runs in a non-bare repository, and is marked as such in the cmd_struct in git.c, the changes do not have to be guarded against running in a bare repository. To test this properly, you need to run t7001 with the environment variable TEST_CTIME_WITH_SLEEP set non-empty, since there is no way to manipulate the ctime directly; we have to sleep. Signed-off-by: Johannes Schindelin <redacted> --- builtin-mv.c | 15 +++++++++++++-- cache.h | 2 +- read-cache.c | 4 ++-- t/t7001-mv.sh | 10 ++++++++-- 4 files changed, 24 insertions(+), 7 deletions(-)
diff --git a/builtin-mv.c b/builtin-mv.c
index 4f65b5a..166a019 100644
--- a/builtin-mv.c
+++ b/builtin-mv.c@@ -214,8 +214,19 @@ int cmd_mv(int argc, const char **argv, const char *prefix) pos = cache_name_pos(src, strlen(src)); assert(pos >= 0); - if (!show_only) - rename_cache_entry_at(pos, dst); + if (!show_only) { + struct stat st; + pos = rename_cache_entry_at(pos, dst); + + /* + * Renaming can update the ctime. Do not force + * a complete rehash just because of that. + */ + if (!lstat(dst, &st)) + active_cache[pos]->ce_ctime = st.st_ctime; + else if (!ignore_errors) + die ("Could not stat '%s'", dst); + } } if (active_cache_changed) {
diff --git a/cache.h b/cache.h
index 8155ab8..4b6876b 100644
--- a/cache.h
+++ b/cache.h@@ -371,7 +371,7 @@ extern int index_name_pos(const struct index_state *, const char *name, int name #define ADD_CACHE_JUST_APPEND 8 /* Append only; tree.c::read_tree() */ extern int add_index_entry(struct index_state *, struct cache_entry *ce, int option); extern struct cache_entry *refresh_cache_entry(struct cache_entry *ce, int really); -extern void rename_index_entry_at(struct index_state *, int pos, const char *new_name); +extern int rename_index_entry_at(struct index_state *, int pos, const char *new_name); extern int remove_index_entry_at(struct index_state *, int pos); extern int remove_file_from_index(struct index_state *, const char *path); #define ADD_CACHE_VERBOSE 1
diff --git a/read-cache.c b/read-cache.c
index c5aa5bc..4454686 100644
--- a/read-cache.c
+++ b/read-cache.c@@ -43,7 +43,7 @@ static void replace_index_entry(struct index_state *istate, int nr, struct cache istate->cache_changed = 1; } -void rename_index_entry_at(struct index_state *istate, int nr, const char *new_name) +int rename_index_entry_at(struct index_state *istate, int nr, const char *new_name) { struct cache_entry *old = istate->cache[nr], *new; int namelen = strlen(new_name);
@@ -56,7 +56,7 @@ void rename_index_entry_at(struct index_state *istate, int nr, const char *new_n cache_tree_invalidate_path(istate->cache_tree, old->name); remove_index_entry_at(istate, nr); - add_index_entry(istate, new, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE); + return add_index_entry(istate, new, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE); } /*
diff --git a/t/t7001-mv.sh b/t/t7001-mv.sh
index 910a28c..5f6cee5 100755
--- a/t/t7001-mv.sh
+++ b/t/t7001-mv.sh@@ -180,12 +180,15 @@ test_expect_success 'git mv should overwrite symlink to a file' ' echo 1 >moved && ln -s moved symlink && git add moved symlink && + if test ! -z "$TEST_CTIME_WITH_SLEEP" + then + sleep 1 + fi && test_must_fail git mv moved symlink && git mv -f moved symlink && ! test -e moved && test -f symlink && test "$(cat symlink)" = 1 && - git update-index --refresh && git diff-files --quiet '
@@ -199,11 +202,14 @@ test_expect_success 'git mv should overwrite file with a symlink' ' echo 1 >moved && ln -s moved symlink && git add moved symlink && + if test ! -z "$TEST_CTIME_WITH_SLEEP" + then + sleep 1 + fi && test_must_fail git mv symlink moved && git mv -f symlink moved && ! test -e symlink && test -h moved && - git update-index --refresh && git diff-files --quiet '
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1.6.0.rc1.55.g69db8