When run with the "-C" option, fast-export writes 'C' commands in its
output whenever the internal diff mechanism detects a file copy,
indicating that fast-import should copy the given existing file to the
given new filename. However, the diff mechanism works against the
prior version of the file, whereas fast-import uses whatever is current.
This causes issues when a commit both modifies a file and uses it as the
source for a copy.
Therefore, teach fast-export to refrain from writing 'C' when it has
already written a modification command for a file.
An existing test in t9350-fast-export is also fixed in this patch. The
existing line "C file6 file7" copies the wrong version of file6, but it
has coincidentally worked because file7 was subsequently overridden.
Reported-by: Juraj Oršulić <juraj.orsulic@xxxxxx>
Signed-off-by: Jonathan Tan <jonathantanmy@xxxxxxxxxx>
---
I tested this with the reproduction commands given by Juraj Oršulić and
it works.
I also have a version that prints the redundant 'C' (and does not
require the change to t9350), omitting it only if it would cause a wrong
result. That seems imprecise to me, but I can send that out if the
redundant 'C' is preferred.
---
builtin/fast-export.c | 46 ++++++++++++++++++++++++++++++++--------------
t/t9350-fast-export.sh | 20 +++++++++++++++++++-
2 files changed, 51 insertions(+), 15 deletions(-)
diff --git a/builtin/fast-export.c b/builtin/fast-export.c
index d412c0a8f..da42ee5e6 100644
--- a/builtin/fast-export.c
+++ b/builtin/fast-export.c
@@ -344,6 +344,7 @@ static void show_filemodify(struct diff_queue_struct *q,
struct diff_options *options, void *data)
{
int i;
+ struct string_list *changed = data;
/*
* Handle files below a directory first, in case they are all deleted
@@ -359,20 +360,31 @@ static void show_filemodify(struct diff_queue_struct *q,
case DIFF_STATUS_DELETED:
printf("D ");
print_path(spec->path);
+ string_list_insert(changed, spec->path);
putchar('\n');
break;
case DIFF_STATUS_COPIED:
case DIFF_STATUS_RENAMED:
- printf("%c ", q->queue[i]->status);
- print_path(ospec->path);
- putchar(' ');
- print_path(spec->path);
- putchar('\n');
-
- if (!oidcmp(&ospec->oid, &spec->oid) &&
- ospec->mode == spec->mode)
- break;
+ /*
+ * If a change in the file corresponding to ospec->path
+ * has been observed, we cannot trust its contents
+ * because the diff is calculated based on the prior
+ * contents, not the current contents. So, declare a
+ * copy or rename only if there was no change observed.
+ */
+ if (!string_list_has_string(changed, ospec->path)) {
+ printf("%c ", q->queue[i]->status);
+ print_path(ospec->path);
+ putchar(' ');
+ print_path(spec->path);
+ string_list_insert(changed, spec->path);
+ putchar('\n');
+
+ if (!oidcmp(&ospec->oid, &spec->oid) &&
+ ospec->mode == spec->mode)
+ break;
+ }
/* fallthrough */
case DIFF_STATUS_TYPE_CHANGED:
@@ -393,6 +405,7 @@ static void show_filemodify(struct diff_queue_struct *q,
get_object_mark(object));
}
print_path(spec->path);
+ string_list_insert(changed, spec->path);
putchar('\n');
break;
@@ -528,7 +541,8 @@ static void anonymize_ident_line(const char **beg, const char **end)
*end = out->buf + out->len;
}
-static void handle_commit(struct commit *commit, struct rev_info *rev)
+static void handle_commit(struct commit *commit, struct rev_info *rev,
+ struct string_list *paths_of_changed_objects)
{
int saved_output_format = rev->diffopt.output_format;
const char *commit_buffer;
@@ -615,6 +629,7 @@ static void handle_commit(struct commit *commit, struct rev_info *rev)
if (full_tree)
printf("deleteall\n");
log_tree_diff_flush(rev);
+ string_list_clear(paths_of_changed_objects, 0);
rev->diffopt.output_format = saved_output_format;
printf("\n");
@@ -630,14 +645,15 @@ static void *anonymize_tag(const void *old, size_t *len)
return strbuf_detach(&out, len);
}
-static void handle_tail(struct object_array *commits, struct rev_info *revs)
+static void handle_tail(struct object_array *commits, struct rev_info *revs,
+ struct string_list *paths_of_changed_objects)
{
struct commit *commit;
while (commits->nr) {
commit = (struct commit *)commits->objects[commits->nr - 1].item;
if (has_unshown_parent(commit))
return;
- handle_commit(commit, revs);
+ handle_commit(commit, revs, paths_of_changed_objects);
commits->nr--;
}
}
@@ -977,6 +993,7 @@ int cmd_fast_export(int argc, const char **argv, const char *prefix)
char *export_filename = NULL, *import_filename = NULL;
uint32_t lastimportid;
struct string_list refspecs_list = STRING_LIST_INIT_NODUP;
+ struct string_list paths_of_changed_objects = STRING_LIST_INIT_DUP;
struct option options[] = {
OPT_INTEGER(0, "progress", &progress,
N_("show progress after <n> objects")),
@@ -1049,14 +1066,15 @@ int cmd_fast_export(int argc, const char **argv, const char *prefix)
if (prepare_revision_walk(&revs))
die("revision walk setup failed");
revs.diffopt.format_callback = show_filemodify;
+ revs.diffopt.format_callback_data = &paths_of_changed_objects;
DIFF_OPT_SET(&revs.diffopt, RECURSIVE);
while ((commit = get_revision(&revs))) {
if (has_unshown_parent(commit)) {
add_object_array(&commit->object, NULL, &commits);
}
else {
- handle_commit(commit, &revs);
- handle_tail(&commits, &revs);
+ handle_commit(commit, &revs, &paths_of_changed_objects);
+ handle_tail(&commits, &revs, &paths_of_changed_objects);
}
}
diff --git a/t/t9350-fast-export.sh b/t/t9350-fast-export.sh
index 8dcb05c4a..866ddf605 100755
--- a/t/t9350-fast-export.sh
+++ b/t/t9350-fast-export.sh
@@ -234,7 +234,7 @@ test_expect_success 'fast-export -C -C | fast-import' '
mkdir new &&
git --git-dir=new/.git init &&
git fast-export -C -C --signed-tags=strip --all > output &&
- grep "^C file6 file7\$" output &&
+ grep "^C file2 file4\$" output &&
cat output |
(cd new &&
git fast-import &&
@@ -522,4 +522,22 @@ test_expect_success 'delete refspec' '
test_cmp expected actual
'
+test_expect_success 'when using -C, do not declare copy when source of copy is also modified' '
+ test_create_repo src &&
+ echo a_line >src/file.txt &&
+ git -C src add file.txt &&
+ git -C src commit -m 1st_commit &&
+
+ cp src/file.txt src/file2.txt &&
+ echo another_line >>src/file.txt &&
+ git -C src add file.txt file2.txt &&
+ git -C src commit -m 2nd_commit &&
+
+ test_create_repo dst &&
+ git -C src fast-export --all -C | git -C dst fast-import &&
+ git -C src show >expected &&
+ git -C dst show >actual &&
+ test_cmp expected actual
+'
+
test_done
--
2.14.1.821.g8fa685d3b7-goog
