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authorJunio C Hamano <gitster@pobox.com>2019-11-10 09:02:13 (GMT)
committerJunio C Hamano <gitster@pobox.com>2019-11-10 09:02:13 (GMT)
commitd9800351d3386db0c306fde03976d8475d7409a6 (patch)
treee2a4b6bff5bc15b9acce073477ab86cc62f50c96 /merge-recursive.c
parent0c51181ffb178a6581ecb471091cbd2d0c48f165 (diff)
parentda1e295e008ba016eef008385afb2c20c7fc3ff8 (diff)
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Merge branch 'en/merge-recursive-directory-rename-fixes'
When all files from some subdirectory were renamed to the root directory, the directory rename heuristics would fail to detect that as a rename/merge of the subdirectory to the root directory, which has been corrected. * en/merge-recursive-directory-rename-fixes: t604[236]: do not run setup in separate tests merge-recursive: fix merging a subdirectory into the root directory merge-recursive: clean up get_renamed_dir_portion()
Diffstat (limited to 'merge-recursive.c')
-rw-r--r--merge-recursive.c104
1 files changed, 81 insertions, 23 deletions
diff --git a/merge-recursive.c b/merge-recursive.c
index 42be7c9..11869ad 100644
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -1951,6 +1951,16 @@ static char *apply_dir_rename(struct dir_rename_entry *entry,
return NULL;
oldlen = strlen(entry->dir);
+ if (entry->new_dir.len == 0)
+ /*
+ * If someone renamed/merged a subdirectory into the root
+ * directory (e.g. 'some/subdir' -> ''), then we want to
+ * avoid returning
+ * '' + '/filename'
+ * as the rename; we need to make old_path + oldlen advance
+ * past the '/' character.
+ */
+ oldlen++;
newlen = entry->new_dir.len + (strlen(old_path) - oldlen) + 1;
strbuf_grow(&new_path, newlen);
strbuf_addbuf(&new_path, &entry->new_dir);
@@ -1963,8 +1973,8 @@ static void get_renamed_dir_portion(const char *old_path, const char *new_path,
char **old_dir, char **new_dir)
{
char *end_of_old, *end_of_new;
- int old_len, new_len;
+ /* Default return values: NULL, meaning no rename */
*old_dir = NULL;
*new_dir = NULL;
@@ -1975,43 +1985,91 @@ static void get_renamed_dir_portion(const char *old_path, const char *new_path,
* "a/b/c/d" was renamed to "a/b/some/thing/else"
* so, for this example, this function returns "a/b/c/d" in
* *old_dir and "a/b/some/thing/else" in *new_dir.
- *
- * Also, if the basename of the file changed, we don't care. We
- * want to know which portion of the directory, if any, changed.
+ */
+
+ /*
+ * If the basename of the file changed, we don't care. We want
+ * to know which portion of the directory, if any, changed.
*/
end_of_old = strrchr(old_path, '/');
end_of_new = strrchr(new_path, '/');
- if (end_of_old == NULL || end_of_new == NULL)
+ /*
+ * If end_of_old is NULL, old_path wasn't in a directory, so there
+ * could not be a directory rename (our rule elsewhere that a
+ * directory which still exists is not considered to have been
+ * renamed means the root directory can never be renamed -- because
+ * the root directory always exists).
+ */
+ if (end_of_old == NULL)
+ return; /* Note: *old_dir and *new_dir are still NULL */
+
+ /*
+ * If new_path contains no directory (end_of_new is NULL), then we
+ * have a rename of old_path's directory to the root directory.
+ */
+ if (end_of_new == NULL) {
+ *old_dir = xstrndup(old_path, end_of_old - old_path);
+ *new_dir = xstrdup("");
return;
+ }
+
+ /* Find the first non-matching character traversing backwards */
while (*--end_of_new == *--end_of_old &&
end_of_old != old_path &&
end_of_new != new_path)
; /* Do nothing; all in the while loop */
+
/*
- * We've found the first non-matching character in the directory
- * paths. That means the current directory we were comparing
- * represents the rename. Move end_of_old and end_of_new back
- * to the full directory name.
+ * If both got back to the beginning of their strings, then the
+ * directory didn't change at all, only the basename did.
*/
- if (*end_of_old == '/')
- end_of_old++;
- if (*end_of_old != '/')
- end_of_new++;
- end_of_old = strchr(end_of_old, '/');
- end_of_new = strchr(end_of_new, '/');
+ if (end_of_old == old_path && end_of_new == new_path &&
+ *end_of_old == *end_of_new)
+ return; /* Note: *old_dir and *new_dir are still NULL */
/*
- * It may have been the case that old_path and new_path were the same
- * directory all along. Don't claim a rename if they're the same.
+ * If end_of_new got back to the beginning of its string, and
+ * end_of_old got back to the beginning of some subdirectory, then
+ * we have a rename/merge of a subdirectory into the root, which
+ * needs slightly special handling.
+ *
+ * Note: There is no need to consider the opposite case, with a
+ * rename/merge of the root directory into some subdirectory
+ * because as noted above the root directory always exists so it
+ * cannot be considered to be renamed.
*/
- old_len = end_of_old - old_path;
- new_len = end_of_new - new_path;
-
- if (old_len != new_len || strncmp(old_path, new_path, old_len)) {
- *old_dir = xstrndup(old_path, old_len);
- *new_dir = xstrndup(new_path, new_len);
+ if (end_of_new == new_path &&
+ end_of_old != old_path && end_of_old[-1] == '/') {
+ *old_dir = xstrndup(old_path, --end_of_old - old_path);
+ *new_dir = xstrdup("");
+ return;
}
+
+ /*
+ * We've found the first non-matching character in the directory
+ * paths. That means the current characters we were looking at
+ * were part of the first non-matching subdir name going back from
+ * the end of the strings. Get the whole name by advancing both
+ * end_of_old and end_of_new to the NEXT '/' character. That will
+ * represent the entire directory rename.
+ *
+ * The reason for the increment is cases like
+ * a/b/star/foo/whatever.c -> a/b/tar/foo/random.c
+ * After dropping the basename and going back to the first
+ * non-matching character, we're now comparing:
+ * a/b/s and a/b/
+ * and we want to be comparing:
+ * a/b/star/ and a/b/tar/
+ * but without the pre-increment, the one on the right would stay
+ * a/b/.
+ */
+ end_of_old = strchr(++end_of_old, '/');
+ end_of_new = strchr(++end_of_new, '/');
+
+ /* Copy the old and new directories into *old_dir and *new_dir. */
+ *old_dir = xstrndup(old_path, end_of_old - old_path);
+ *new_dir = xstrndup(new_path, end_of_new - new_path);
}
static void remove_hashmap_entries(struct hashmap *dir_renames,