diff options
Diffstat (limited to 'builtin/difftool.c')
| -rw-r--r-- | builtin/difftool.c | 51 |
1 files changed, 46 insertions, 5 deletions
diff --git a/builtin/difftool.c b/builtin/difftool.c index d13350ce8..25e54ad3e 100644 --- a/builtin/difftool.c +++ b/builtin/difftool.c @@ -254,6 +254,49 @@ static int ensure_leading_directories(char *path) } } +/* + * Unconditional writing of a plain regular file is what + * "git difftool --dir-diff" wants to do for symlinks. We are preparing two + * temporary directories to be fed to a Git-unaware tool that knows how to + * show a diff of two directories (e.g. "diff -r A B"). + * + * Because the tool is Git-unaware, if a symbolic link appears in either of + * these temporary directories, it will try to dereference and show the + * difference of the target of the symbolic link, which is not what we want, + * as the goal of the dir-diff mode is to produce an output that is logically + * equivalent to what "git diff" produces. + * + * Most importantly, we want to get textual comparison of the result of the + * readlink(2). get_symlink() provides that---it returns the contents of + * the symlink that gets written to a regular file to force the external tool + * to compare the readlink(2) result as text, even on a filesystem that is + * capable of doing a symbolic link. + */ +static char *get_symlink(const struct object_id *oid, const char *path) +{ + char *data; + if (is_null_oid(oid)) { + /* The symlink is unknown to Git so read from the filesystem */ + struct strbuf link = STRBUF_INIT; + if (has_symlinks) { + if (strbuf_readlink(&link, path, strlen(path))) + die(_("could not read symlink %s"), path); + } else if (strbuf_read_file(&link, path, 128)) + die(_("could not read symlink file %s"), path); + + data = strbuf_detach(&link, NULL); + } else { + enum object_type type; + unsigned long size; + data = read_sha1_file(oid->hash, &type, &size); + if (!data) + die(_("could not read object %s for symlink %s"), + oid_to_hex(oid), path); + } + + return data; +} + static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix, int argc, const char **argv) { @@ -270,8 +313,6 @@ static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix, struct hashmap working_tree_dups, submodules, symlinks2; struct hashmap_iter iter; struct pair_entry *entry; - enum object_type type; - unsigned long size; struct index_state wtindex; struct checkout lstate, rstate; int rc, flags = RUN_GIT_CMD, err = 0; @@ -377,13 +418,13 @@ static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix, } if (S_ISLNK(lmode)) { - char *content = read_sha1_file(loid.hash, &type, &size); + char *content = get_symlink(&loid, src_path); add_left_or_right(&symlinks2, src_path, content, 0); free(content); } if (S_ISLNK(rmode)) { - char *content = read_sha1_file(roid.hash, &type, &size); + char *content = get_symlink(&roid, dst_path); add_left_or_right(&symlinks2, dst_path, content, 1); free(content); } @@ -397,7 +438,7 @@ static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix, return error("could not write '%s'", src_path); } - if (rmode) { + if (rmode && !S_ISLNK(rmode)) { struct working_tree_entry *entry; /* Avoid duplicate working_tree entries */ |