checkout-index: delay automatic setting of to_tempfile

Using --stage=all requires writing to tempfiles, since we cannot put
multiple stages into a single file. So --stage=all implies --temp.

But we do so by setting to_tempfile in the options callback for --stage,
rather than after all options have been parsed. This leads to two bugs:

  1. If you run "checkout-index --stage=all --stage=2", this should not
     imply --temp, but it currently does. The callback cannot just unset
     to_tempfile when it sees the "2" value, because it no longer knows
     if its value was from the earlier --stage call, or if the user
     specified --temp explicitly.

  2. If you run "checkout-index --stage=all --no-temp", the --no-temp
     will overwrite the earlier implied --temp. But this mode of
     operation cannot work, and the command will fail with "<path>
     already exists" when trying to write the higher stages.

We can fix both by lazily setting to_tempfile. We'll make it a tristate,
with -1 as "not yet given", and have --stage=all enable it only after
all options are parsed. Likewise, after all options are parsed we can
detect and reject the bogus "--no-temp" case.

Note that this does technically change the behavior for "--stage=all
--no-temp" for paths which have only one stage present (which
accidentally worked before, but is now forbidden). But this behavior was
never intended, and you'd have to go out of your way to try to trigger
it.

The new tests cover both cases, as well the general "--stage=all implies
--temp", as most of the other tests explicitly say "--temp". Ironically,
the test "checkout --temp within subdir" is the only one that _doesn't_
use "--temp", and so was implicitly covering this case. But it seems
reasonable to have a more explicit test alongside the other related
ones.

Suggested-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/checkout-index.c b/builtin/checkout-index.c
index f62f13f2b5324e15f982071f73b24281d2d9637a..526c210bcb1d271b9e2a5c35b4f6c1c78f0a18bd 100644 (file)
--- a/builtin/checkout-index.c
+++ b/builtin/checkout-index.c
@@ -24,7 +24,7 @@
 static int nul_term_line;
 static int checkout_stage; /* default to checkout stage0 */
 static int ignore_skip_worktree; /* default to 0 */
-static int to_tempfile;
+static int to_tempfile = -1;
 static char topath[4][TEMPORARY_FILENAME_LENGTH + 1];
 
 static struct checkout state = CHECKOUT_INIT;
@@ -196,7 +196,6 @@ static int option_parse_stage(const struct option *opt,
        BUG_ON_OPT_NEG(unset);
 
        if (!strcmp(arg, "all")) {
-               to_tempfile = 1;
                checkout_stage = CHECKOUT_ALL;
        } else {
                int ch = arg[0];
@@ -269,6 +268,12 @@ int cmd_checkout_index(int argc, const char **argv, const char *prefix)
                state.base_dir = "";
        state.base_dir_len = strlen(state.base_dir);
 
+       if (to_tempfile < 0)
+               to_tempfile = (checkout_stage == CHECKOUT_ALL);
+       if (!to_tempfile && checkout_stage == CHECKOUT_ALL)
+               die(_("options '%s' and '%s' cannot be used together"),
+                   "--stage=all", "--no-temp");
+
        /*
         * when --prefix is specified we do not want to update cache.
         */

diff --git a/t/t2004-checkout-cache-temp.sh b/t/t2004-checkout-cache-temp.sh
index b16d69ca4ae0e8b61ce00a085273d8ad6f40f104..45dd1bc8582142db6d35c7e1d708c8a27c243a34 100755 (executable)
--- a/t/t2004-checkout-cache-temp.sh
+++ b/t/t2004-checkout-cache-temp.sh
@@ -117,6 +117,26 @@ test_expect_success 'checkout all stages/one file to temporary files' '
        test $(cat $s3) = tree3path1)
 '
 
+test_expect_success '--stage=all implies --temp' '
+       rm -f path* .merge_* actual &&
+       git checkout-index --stage=all -- path1 &&
+       test_path_is_missing path1
+'
+
+test_expect_success 'overriding --stage=all resets implied --temp' '
+       rm -f path* .merge_* actual &&
+       git checkout-index --stage=all --stage=2 -- path1 &&
+       echo tree2path1 >expect &&
+       test_cmp expect path1
+'
+
+test_expect_success '--stage=all --no-temp is rejected' '
+       rm -f path* .merge_* actual &&
+       test_must_fail git checkout-index --stage=all --no-temp -- path1 2>err &&
+       grep -v "already exists" err &&
+       grep "options .--stage=all. and .--no-temp. cannot be used together" err
+'
+
 test_expect_success 'checkout some stages/one file to temporary files' '
        rm -f path* .merge_* actual &&
        git checkout-index --stage=all --temp -- path2 >actual &&