diff options
| -rw-r--r-- | builtin/difftool.c | 51 | ||||
| -rwxr-xr-x | t/t7800-difftool.sh | 67 |
2 files changed, 111 insertions, 7 deletions
diff --git a/builtin/difftool.c b/builtin/difftool.c index d13350ce83..25e54ad3ed 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 */ diff --git a/t/t7800-difftool.sh b/t/t7800-difftool.sh index 25241f4096..0e7f30db2d 100755 --- a/t/t7800-difftool.sh +++ b/t/t7800-difftool.sh @@ -428,7 +428,7 @@ run_dir_diff_test 'difftool --dir-diff branch from subdirectory' ' git difftool --dir-diff $symlinks --extcmd ls branch >output && # "sub" must only exist in "right" # "file" and "file2" must be listed in both "left" and "right" - grep sub output > sub-output && + grep sub output >sub-output && test_line_count = 1 sub-output && grep file"$" output >file-output && test_line_count = 2 file-output && @@ -591,6 +591,7 @@ test_expect_success 'difftool --no-symlinks detects conflict ' ' ' test_expect_success 'difftool properly honors gitlink and core.worktree' ' + test_when_finished rm -rf submod/ule && git submodule add ./. submod/ule && test_config -C submod/ule diff.tool checktrees && test_config -C submod/ule difftool.checktrees.cmd '\'' @@ -600,11 +601,13 @@ test_expect_success 'difftool properly honors gitlink and core.worktree' ' cd submod/ule && echo good >expect && git difftool --tool=checktrees --dir-diff HEAD~ >actual && - test_cmp expect actual + test_cmp expect actual && + rm -f expect actual ) ' test_expect_success SYMLINKS 'difftool --dir-diff symlinked directories' ' + test_when_finished git reset --hard && git init dirlinks && ( cd dirlinks && @@ -623,4 +626,64 @@ test_expect_success SYMLINKS 'difftool --dir-diff symlinked directories' ' ) ' +test_expect_success SYMLINKS 'difftool --dir-diff handles modified symlinks' ' + test_when_finished git reset --hard && + touch b && + ln -s b c && + git add b c && + test_tick && + git commit -m initial && + touch d && + rm c && + ln -s d c && + cat >expect <<-EOF && + b + c + + c + EOF + git difftool --symlinks --dir-diff --extcmd ls >output && + grep -v ^/ output >actual && + test_cmp expect actual && + + git difftool --no-symlinks --dir-diff --extcmd ls >output && + grep -v ^/ output >actual && + test_cmp expect actual && + + # The left side contains symlink "c" that points to "b" + test_config difftool.cat.cmd "cat \$LOCAL/c" && + printf "%s\n" b >expect && + + git difftool --symlinks --dir-diff --tool cat >actual && + test_cmp expect actual && + + git difftool --symlinks --no-symlinks --dir-diff --tool cat >actual && + test_cmp expect actual && + + # The right side contains symlink "c" that points to "d" + test_config difftool.cat.cmd "cat \$REMOTE/c" && + printf "%s\n" d >expect && + + git difftool --symlinks --dir-diff --tool cat >actual && + test_cmp expect actual && + + git difftool --no-symlinks --dir-diff --tool cat >actual && + test_cmp expect actual && + + # Deleted symlinks + rm -f c && + cat >expect <<-EOF && + b + c + + EOF + git difftool --symlinks --dir-diff --extcmd ls >output && + grep -v ^/ output >actual && + test_cmp expect actual && + + git difftool --no-symlinks --dir-diff --extcmd ls >output && + grep -v ^/ output >actual && + test_cmp expect actual +' + test_done |