* [PATCH v4 0/3] difftool dir-diff symlink bug fix and cleanup patches @ 2021-09-19 20:38 David Aguilar 2021-09-19 20:38 ` [PATCH v4 1/3] difftool: fix symlink-file writing in dir-diff mode David Aguilar ` (3 more replies) 0 siblings, 4 replies; 10+ messages in thread From: David Aguilar @ 2021-09-19 20:38 UTC (permalink / raw) To: Junio C Hamano Cc: Git Mailing List, Johannes Schindelin, Alan Blotz, Đoàn Trần Công Danh, Ævar Arnfjörð Bjarmason, Jeff King This patch series fixes a regression in difftool that can lead to data loss. The symlink-file writing in difftool's dir-diff mode has been fixed to no longer write-through to the symlink targets. Please consider patching older Git versions with the fix from 1/3. Changes since last time: - This series has been reordered so that 1/3 is the patch that fixes the bug. The subsequent patches are cleanup. - Patch 1/4 from before, which removed the tmp test repos, has been dropped. - Patch 1/3 was updated to not remove its tmp test repo. - Patch 1/3 was updated to consistently use "echo" in its tests. - Patch 1/3 was updated to fix a "syminks" -> "symlinks" test comment typo. - Patch 2/3 was reworded to improve the repeated slashes justification. - Patch 3/3 "add a missing space to the ... comments" is unchanged. David Aguilar (3): difftool: fix symlink-file writing in dir-diff mode difftool: use a strbuf to create a tmpdir path without double-slashes difftool: add a missing space to the run_dir_diff() comments builtin/difftool.c | 32 ++++++++++--------- t/t7800-difftool.sh | 75 +++++++++++++++++++++++++++++++++++++++++++-- 2 files changed, 91 insertions(+), 16 deletions(-) -- 2.33.0.720.g5b0b3ce580 ^ permalink raw reply [flat|nested] 10+ messages in thread
* [PATCH v4 1/3] difftool: fix symlink-file writing in dir-diff mode 2021-09-19 20:38 [PATCH v4 0/3] difftool dir-diff symlink bug fix and cleanup patches David Aguilar @ 2021-09-19 20:38 ` David Aguilar 2021-09-20 7:59 ` Ævar Arnfjörð Bjarmason 2021-09-19 20:38 ` [PATCH v4 2/3] difftool: use a strbuf to create a tmpdir path without repeated slashes David Aguilar ` (2 subsequent siblings) 3 siblings, 1 reply; 10+ messages in thread From: David Aguilar @ 2021-09-19 20:38 UTC (permalink / raw) To: Junio C Hamano Cc: Git Mailing List, Johannes Schindelin, Alan Blotz, Đoàn Trần Công Danh, Ævar Arnfjörð Bjarmason, Jeff King The difftool dir-diff mode handles symlinks by replacing them with their readlink(2) values. This allows diff tools to see changes to symlinks as if they were regular text diffs with the old and new path values. This is analogous to what "git diff" displays when symlinks change. The temporary diff directories that are created initially contain symlinks because they get checked-out using a temporary index that retains the original symlinks as checked-in to the repository. A bug was introduced when difftool was rewritten in C that made difftool write the readlink(2) contents into the pointed-to file rather than the symlink itself. The write was going through the symlink and writing to its target rather than writing to the symlink path itself. Replace symlinks with raw text files by unlinking the symlink path before writing the readlink(2) content into them. When 18ec800512eb0634a0bf5e86b36ed156fbee73f3 added handling for modified symlinks this bug got recorded in the test suite. The tests included the pointed-to symlink target paths. These paths were being reported because difftool was erroneously writing to them, but they should have never been reported nor written. Correct the modified-symlinks test cases by removing the target files from the expected output. Add a test to ensure that symlinks are written with the readlink(2) values and that the target files contain their original content. Reported-by: Alan Blotz <work@blotz.org> Helped-by: Đoàn Trần Công Danh <congdanhqx@gmail.com> Signed-off-by: David Aguilar <davvid@gmail.com> --- builtin/difftool.c | 2 ++ t/t7800-difftool.sh | 68 +++++++++++++++++++++++++++++++++++++++++++-- 2 files changed, 68 insertions(+), 2 deletions(-) diff --git a/builtin/difftool.c b/builtin/difftool.c index bb9fe7245a..21e055d13a 100644 --- a/builtin/difftool.c +++ b/builtin/difftool.c @@ -557,11 +557,13 @@ static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix, if (*entry->left) { add_path(&ldir, ldir_len, entry->path); ensure_leading_directories(ldir.buf); + unlink(ldir.buf); write_file(ldir.buf, "%s", entry->left); } if (*entry->right) { add_path(&rdir, rdir_len, entry->path); ensure_leading_directories(rdir.buf); + unlink(rdir.buf); write_file(rdir.buf, "%s", entry->right); } } diff --git a/t/t7800-difftool.sh b/t/t7800-difftool.sh index a173f564bc..07a52fb8e1 100755 --- a/t/t7800-difftool.sh +++ b/t/t7800-difftool.sh @@ -674,7 +674,6 @@ test_expect_success SYMLINKS 'difftool --dir-diff handles modified symlinks' ' rm c && ln -s d c && cat >expect <<-EOF && - b c c @@ -710,7 +709,6 @@ test_expect_success SYMLINKS 'difftool --dir-diff handles modified symlinks' ' # Deleted symlinks rm -f c && cat >expect <<-EOF && - b c EOF @@ -723,6 +721,72 @@ test_expect_success SYMLINKS 'difftool --dir-diff handles modified symlinks' ' test_cmp expect actual ' +test_expect_success SYMLINKS 'difftool --dir-diff writes symlinks as raw text' ' + # Start out on a branch called "branch-init". + git init -b branch-init symlink-files && + ( + cd ./symlink-files && + + # This test ensures that symlinks are written as raw text. + # The "cat" tools output link and file contents. + git config difftool.cat-left-link.cmd "cat \"\$LOCAL/link\"" && + git config difftool.cat-left-a.cmd "cat \"\$LOCAL/file-a\"" && + git config difftool.cat-right-link.cmd "cat \"\$REMOTE/link\"" && + git config difftool.cat-right-b.cmd "cat \"\$REMOTE/file-b\"" && + + # Record the empty initial state so that we can come back here + # later and not have to consider the any cases where difftool + # will create symlinks back into the worktree. + test_tick && + git commit --allow-empty -m init && + + # Create a file called "file-a" with a symlink pointing to it. + git switch -c branch-a && + echo a >file-a && + ln -s file-a link && + git add file-a link && + test_tick && + git commit -m link-to-file-a && + + # Create a file called "file-b" and point the symlink to it. + git switch -c branch-b && + echo b >file-b && + rm link && + ln -s file-b link && + git add file-b link && + git rm file-a && + test_tick && + git commit -m link-to-file-b && + + # Checkout the initial branch so that the --symlinks behavior is + # not activated. The two directories should be completely + # independent with no symlinks pointing back here. + git switch branch-init && + + # The left link must be "file-a" and "file-a" must contain "a". + echo file-a >expect && + git difftool --symlinks --dir-diff --tool cat-left-link \ + branch-a branch-b >actual && + test_cmp expect actual && + + echo a >expect && + git difftool --symlinks --dir-diff --tool cat-left-a \ + branch-a branch-b >actual && + test_cmp expect actual && + + # The right link must be "file-b" and "file-b" must contain "b". + echo file-b >expect && + git difftool --symlinks --dir-diff --tool cat-right-link \ + branch-a branch-b >actual && + test_cmp expect actual && + + echo b >expect && + git difftool --symlinks --dir-diff --tool cat-right-b \ + branch-a branch-b >actual && + test_cmp expect actual + ) +' + test_expect_success 'add -N and difftool -d' ' test_when_finished git reset --hard && -- 2.33.0.720.g5b0b3ce580 ^ permalink raw reply related [flat|nested] 10+ messages in thread
* Re: [PATCH v4 1/3] difftool: fix symlink-file writing in dir-diff mode 2021-09-19 20:38 ` [PATCH v4 1/3] difftool: fix symlink-file writing in dir-diff mode David Aguilar @ 2021-09-20 7:59 ` Ævar Arnfjörð Bjarmason 0 siblings, 0 replies; 10+ messages in thread From: Ævar Arnfjörð Bjarmason @ 2021-09-20 7:59 UTC (permalink / raw) To: David Aguilar Cc: Junio C Hamano, Git Mailing List, Johannes Schindelin, Alan Blotz, Đoàn Trần Công Danh, Jeff King On Sun, Sep 19 2021, David Aguilar wrote: > The difftool dir-diff mode handles symlinks by replacing them with their > readlink(2) values. This allows diff tools to see changes to symlinks > as if they were regular text diffs with the old and new path values. > This is analogous to what "git diff" displays when symlinks change. > > The temporary diff directories that are created initially contain > symlinks because they get checked-out using a temporary index that > retains the original symlinks as checked-in to the repository. > > A bug was introduced when difftool was rewritten in C that made > difftool write the readlink(2) contents into the pointed-to file rather > than the symlink itself. The write was going through the symlink and > writing to its target rather than writing to the symlink path itself. > > Replace symlinks with raw text files by unlinking the symlink path > before writing the readlink(2) content into them. > > When 18ec800512eb0634a0bf5e86b36ed156fbee73f3 added handling for Nit: Please format commits like this: 18ec800512e (difftool: handle modified symlinks in dir-diff mode, 2017-03-15) See "git show -s --pretty=reference" in Documentation/SubmittingPatches. > modified symlinks this bug got recorded in the test suite. The tests > included the pointed-to symlink target paths. These paths were being > reported because difftool was erroneously writing to them, but they > should have never been reported nor written. > > Correct the modified-symlinks test cases by removing the target files > from the expected output. > > Add a test to ensure that symlinks are written with the readlink(2) > values and that the target files contain their original content. > > Reported-by: Alan Blotz <work@blotz.org> > Helped-by: Đoàn Trần Công Danh <congdanhqx@gmail.com> > Signed-off-by: David Aguilar <davvid@gmail.com> > --- > builtin/difftool.c | 2 ++ > t/t7800-difftool.sh | 68 +++++++++++++++++++++++++++++++++++++++++++-- > 2 files changed, 68 insertions(+), 2 deletions(-) > > diff --git a/builtin/difftool.c b/builtin/difftool.c > index bb9fe7245a..21e055d13a 100644 > --- a/builtin/difftool.c > +++ b/builtin/difftool.c > @@ -557,11 +557,13 @@ static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix, > if (*entry->left) { > add_path(&ldir, ldir_len, entry->path); > ensure_leading_directories(ldir.buf); > + unlink(ldir.buf); > write_file(ldir.buf, "%s", entry->left); > } > if (*entry->right) { > add_path(&rdir, rdir_len, entry->path); > ensure_leading_directories(rdir.buf); > + unlink(rdir.buf); > write_file(rdir.buf, "%s", entry->right); > } > } > diff --git a/t/t7800-difftool.sh b/t/t7800-difftool.sh > index a173f564bc..07a52fb8e1 100755 > --- a/t/t7800-difftool.sh > +++ b/t/t7800-difftool.sh > @@ -674,7 +674,6 @@ test_expect_success SYMLINKS 'difftool --dir-diff handles modified symlinks' ' > rm c && > ln -s d c && > cat >expect <<-EOF && > - b > c > > c > @@ -710,7 +709,6 @@ test_expect_success SYMLINKS 'difftool --dir-diff handles modified symlinks' ' > # Deleted symlinks > rm -f c && > cat >expect <<-EOF && > - b > c > > EOF > @@ -723,6 +721,72 @@ test_expect_success SYMLINKS 'difftool --dir-diff handles modified symlinks' ' > test_cmp expect actual > ' > > +test_expect_success SYMLINKS 'difftool --dir-diff writes symlinks as raw text' ' > + # Start out on a branch called "branch-init". > + git init -b branch-init symlink-files && > + ( > + cd ./symlink-files && The "./" isn't needed Neither of those small comments needs a re-roll I think, just reading through & noting things I spotted... I've omitted things that Eric mentioned in <CAPig+cTBfP5_czsPiALcF3tODJmNfXvNkTjqVFRbHCS535d-ng@mail.gmail.com>. ^ permalink raw reply [flat|nested] 10+ messages in thread
* [PATCH v4 2/3] difftool: use a strbuf to create a tmpdir path without repeated slashes 2021-09-19 20:38 [PATCH v4 0/3] difftool dir-diff symlink bug fix and cleanup patches David Aguilar 2021-09-19 20:38 ` [PATCH v4 1/3] difftool: fix symlink-file writing in dir-diff mode David Aguilar @ 2021-09-19 20:38 ` David Aguilar 2021-09-20 5:40 ` Eric Sunshine 2021-09-19 20:38 ` [PATCH v4 3/3] difftool: add a missing space to the run_dir_diff() comments David Aguilar 2021-09-20 18:39 ` [PATCH v4 0/3] difftool dir-diff symlink bug fix and cleanup patches Junio C Hamano 3 siblings, 1 reply; 10+ messages in thread From: David Aguilar @ 2021-09-19 20:38 UTC (permalink / raw) To: Junio C Hamano Cc: Git Mailing List, Johannes Schindelin, Alan Blotz, Đoàn Trần Công Danh, Ævar Arnfjörð Bjarmason, Jeff King The paths generated by difftool are passed to user-facing diff tools. Using paths with repeated slashes in them is a cosmetic blemish that is exposed to users and can be avoided. Use a strbuf to create the buffer used for the dir-diff tmpdir. Strip trailing slashes from the value read from TMPDIR to avoid repeated slashes in the generated paths. Add a unit test to ensure that repeated slashes are not present. Signed-off-by: David Aguilar <davvid@gmail.com> --- builtin/difftool.c | 28 +++++++++++++++------------- t/t7800-difftool.sh | 7 +++++++ 2 files changed, 22 insertions(+), 13 deletions(-) diff --git a/builtin/difftool.c b/builtin/difftool.c index 21e055d13a..daa438be09 100644 --- a/builtin/difftool.c +++ b/builtin/difftool.c @@ -252,11 +252,10 @@ static void changed_files(struct hashmap *result, const char *index_path, strbuf_release(&buf); } -static NORETURN void exit_cleanup(const char *tmpdir, int exit_code) +static NORETURN void exit_cleanup(struct strbuf *buf, int exit_code) { - struct strbuf buf = STRBUF_INIT; - strbuf_addstr(&buf, tmpdir); - remove_dir_recursively(&buf, 0); + remove_dir_recursively(buf, 0); + strbuf_release(buf); if (exit_code) warning(_("failed: %d"), exit_code); exit(exit_code); @@ -333,11 +332,11 @@ static int checkout_path(unsigned mode, struct object_id *oid, static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix, struct child_process *child) { - char tmpdir[PATH_MAX]; struct strbuf info = STRBUF_INIT, lpath = STRBUF_INIT; struct strbuf rpath = STRBUF_INIT, buf = STRBUF_INIT; struct strbuf ldir = STRBUF_INIT, rdir = STRBUF_INIT; struct strbuf wtdir = STRBUF_INIT; + struct strbuf tmpdir = STRBUF_INIT; char *lbase_dir, *rbase_dir; size_t ldir_len, rdir_len, wtdir_len; const char *workdir, *tmp; @@ -360,11 +359,13 @@ static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix, /* Setup temp directories */ tmp = getenv("TMPDIR"); - xsnprintf(tmpdir, sizeof(tmpdir), "%s/git-difftool.XXXXXX", tmp ? tmp : "/tmp"); - if (!mkdtemp(tmpdir)) - return error("could not create '%s'", tmpdir); - strbuf_addf(&ldir, "%s/left/", tmpdir); - strbuf_addf(&rdir, "%s/right/", tmpdir); + strbuf_add_absolute_path(&tmpdir, tmp ? tmp : "/tmp"); + strbuf_trim_trailing_dir_sep(&tmpdir); + strbuf_addstr(&tmpdir, "/git-difftool.XXXXXX"); + if (!mkdtemp(tmpdir.buf)) + return error("could not create '%s'", tmpdir.buf); + strbuf_addf(&ldir, "%s/left/", tmpdir.buf); + strbuf_addf(&rdir, "%s/right/", tmpdir.buf); strbuf_addstr(&wtdir, workdir); if (!wtdir.len || !is_dir_sep(wtdir.buf[wtdir.len - 1])) strbuf_addch(&wtdir, '/'); @@ -614,7 +615,7 @@ static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix, if (!indices_loaded) { struct lock_file lock = LOCK_INIT; strbuf_reset(&buf); - strbuf_addf(&buf, "%s/wtindex", tmpdir); + strbuf_addf(&buf, "%s/wtindex", tmpdir.buf); if (hold_lock_file_for_update(&lock, buf.buf, 0) < 0 || write_locked_index(&wtindex, &lock, COMMIT_LOCK)) { ret = error("could not write %s", buf.buf); @@ -644,11 +645,11 @@ static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix, } if (err) { - warning(_("temporary files exist in '%s'."), tmpdir); + warning(_("temporary files exist in '%s'."), tmpdir.buf); warning(_("you may want to cleanup or recover these.")); exit(1); } else - exit_cleanup(tmpdir, rc); + exit_cleanup(&tmpdir, rc); finish: if (fp) @@ -660,6 +661,7 @@ static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix, strbuf_release(&rdir); strbuf_release(&wtdir); strbuf_release(&buf); + strbuf_release(&tmpdir); return ret; } diff --git a/t/t7800-difftool.sh b/t/t7800-difftool.sh index 07a52fb8e1..0670b617b4 100755 --- a/t/t7800-difftool.sh +++ b/t/t7800-difftool.sh @@ -453,6 +453,13 @@ run_dir_diff_test 'difftool --dir-diff' ' grep "^file$" output ' +run_dir_diff_test 'difftool --dir-diff avoids repeated slashes in TMPDIR' ' + TMPDIR="${TMPDIR:-/tmp}////" \ + git difftool --dir-diff $symlinks --extcmd echo branch >output && + grep -v // output >actual && + test_line_count = 1 actual +' + run_dir_diff_test 'difftool --dir-diff ignores --prompt' ' git difftool --dir-diff $symlinks --prompt --extcmd ls branch >output && grep "^sub$" output && -- 2.33.0.720.g5b0b3ce580 ^ permalink raw reply related [flat|nested] 10+ messages in thread
* Re: [PATCH v4 2/3] difftool: use a strbuf to create a tmpdir path without repeated slashes 2021-09-19 20:38 ` [PATCH v4 2/3] difftool: use a strbuf to create a tmpdir path without repeated slashes David Aguilar @ 2021-09-20 5:40 ` Eric Sunshine 2021-09-20 22:08 ` [PATCH v5] difftool: " David Aguilar 0 siblings, 1 reply; 10+ messages in thread From: Eric Sunshine @ 2021-09-20 5:40 UTC (permalink / raw) To: David Aguilar Cc: Junio C Hamano, Git Mailing List, Johannes Schindelin, Alan Blotz, Đoàn Trần Công Danh, Ævar Arnfjörð Bjarmason, Jeff King On Sun, Sep 19, 2021 at 4:38 PM David Aguilar <davvid@gmail.com> wrote: > difftool: use a strbuf to create a tmpdir path without repeated slashes > > The paths generated by difftool are passed to user-facing diff tools. > Using paths with repeated slashes in them is a cosmetic blemish that > is exposed to users and can be avoided. > > Use a strbuf to create the buffer used for the dir-diff tmpdir. > Strip trailing slashes from the value read from TMPDIR to avoid > repeated slashes in the generated paths. Mentioning strbuf in the commit message misleads the reviewer into thinking that it somehow merits extra attention and close scrutiny. In fact, the opposite is true: strbuf is just an implementation detail; there is no reason to mention it in the commit message at all. The commit message's emphasis on strbuf distracts the reader from the real purpose of this change, which is to fix a cosmetic issue (and maybe a real issue on Windows in which double-slash can have significance?). So, perhaps: difftool: fold out repeated slashes from TMPDIR Paths generated by difftool are passed to user-facing diff tools. Supplying paths with repeated slashes is a cosmetic blemish that is exposed to users and can be avoided. Therefore, strip trailing slashes from the value of TMPDIR to avoid repeated slashes in the generated paths. > Add a unit test to ensure that repeated slashes are not present. Unless there is something unusual or tricky about the new test that requires extra explanation in the commit message, there is little reason to mention that you're adding a new test, so I'd probably drop this line, as well. After all, the patch easily speaks for itself, and a reviewer can see at a glance that you're adding a new test. > diff --git a/builtin/difftool.c b/builtin/difftool.c > @@ -252,11 +252,10 @@ static void changed_files(struct hashmap *result, const char *index_path, > -static NORETURN void exit_cleanup(const char *tmpdir, int exit_code) > +static NORETURN void exit_cleanup(struct strbuf *buf, int exit_code) > { > - struct strbuf buf = STRBUF_INIT; > - strbuf_addstr(&buf, tmpdir); > - remove_dir_recursively(&buf, 0); > + remove_dir_recursively(buf, 0); > + strbuf_release(buf); > if (exit_code) > warning(_("failed: %d"), exit_code); > exit(exit_code); It feels wrong to be releasing the caller-supplied strbuf; this change makes it harder to reason about ownership. Normally, the entity which allocates a resource should be the one to release it. More on this below... > @@ -333,11 +332,11 @@ static int checkout_path(unsigned mode, struct object_id *oid, > + struct strbuf tmpdir = STRBUF_INIT; > + strbuf_add_absolute_path(&tmpdir, tmp ? tmp : "/tmp"); > + strbuf_trim_trailing_dir_sep(&tmpdir); > + strbuf_addstr(&tmpdir, "/git-difftool.XXXXXX"); > + if (!mkdtemp(tmpdir.buf)) > + return error("could not create '%s'", tmpdir.buf); Leaking the `tmpdir` strbuf here. You'd want: if (!mkdtemp(tmpdir.buf)) { error("could not create '%s'", tmpdir.buf); strbuf_release(&tmpdir); return -1; } > @@ -644,11 +645,11 @@ static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix, > if (err) { > - warning(_("temporary files exist in '%s'."), tmpdir); > + warning(_("temporary files exist in '%s'."), tmpdir.buf); > warning(_("you may want to cleanup or recover these.")); > exit(1); > } else > - exit_cleanup(tmpdir, rc); > + exit_cleanup(&tmpdir, rc); ... [continued from above] Both branches in this conditional terminate the program either directly by `exit(1)` or indirectly through `exit_cleanup(...)`. Yet only the `exit_cleanup(...)` branch releases the strbuf (because you updated `exit_cleanup()` above to do so); the other branch just leaks the strbuf. This is inconsistent. Since we're exiting anyhow, and since `exit_cleanup()` was already leaking its own strbuf even before this patch, and since it feels somewhat dirty to have `exit_cleanup()` responsible for releasing a resource it didn't allocate, it may make sense just to maintain the status-quo and just leak the strbuf before exiting. That is, don't make any changes to `exit_cleanup()`, and let both of these branches leak the strbuf. On the other hand, if you really do want to release the strbuf, then it would be more consistent for both branches in this conditional to do so, not just one. That is, add a strbuf_release() to the `then` arm. > finish: > if (fp) > @@ -660,6 +661,7 @@ static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix, > strbuf_release(&rdir); > strbuf_release(&wtdir); > strbuf_release(&buf); > + strbuf_release(&tmpdir); Correctly releasing the strbuf. Good. ^ permalink raw reply [flat|nested] 10+ messages in thread
* [PATCH v5] difftool: create a tmpdir path without repeated slashes 2021-09-20 5:40 ` Eric Sunshine @ 2021-09-20 22:08 ` David Aguilar 0 siblings, 0 replies; 10+ messages in thread From: David Aguilar @ 2021-09-20 22:08 UTC (permalink / raw) To: Junio C Hamano Cc: Git Mailing List, Johannes Schindelin, Alan Blotz, Đoàn Trần Công Danh, Eric Sunshine, Jeff King The paths generated by difftool are passed to user-facing diff tools. Using paths with repeated slashes in them is a cosmetic blemish that is exposed to users and can be avoided. Use a strbuf to create the buffer used for the dir-diff tmpdir. Strip trailing slashes from the value read from TMPDIR to avoid repeated slashes in the generated paths. Adjust the error handling to avoid leaking strbufs. Signed-off-by: David Aguilar <davvid@gmail.com> --- This is a replacement patch for 976bce8a6d (difftool: use a strbuf to create a tmpdir path without repeated slashes, 2021-09-19) currently in da/difftool (seen). Changes since last v4: - The strbuf leaks noted by Eric have been plugged. - More variables are initialized so that the finish: section can run without using unitialized variables. - Reworked the control flow so that we always "goto finish" on error. - Got rid of exit_cleanup() entirely -- there's no need for a separate function. - Reworded the commit message to fold in Ævar's sugs. builtin/difftool.c | 48 ++++++++++++++++++++++----------------------- t/t7800-difftool.sh | 7 +++++++ 2 files changed, 30 insertions(+), 25 deletions(-) diff --git a/builtin/difftool.c b/builtin/difftool.c index 2df6af9e5a..a972431f6d 100644 --- a/builtin/difftool.c +++ b/builtin/difftool.c @@ -252,16 +252,6 @@ static void changed_files(struct hashmap *result, const char *index_path, strbuf_release(&buf); } -static NORETURN void exit_cleanup(const char *tmpdir, int exit_code) -{ - struct strbuf buf = STRBUF_INIT; - strbuf_addstr(&buf, tmpdir); - remove_dir_recursively(&buf, 0); - if (exit_code) - warning(_("failed: %d"), exit_code); - exit(exit_code); -} - static int ensure_leading_directories(char *path) { switch (safe_create_leading_directories(path)) { @@ -333,16 +323,16 @@ static int checkout_path(unsigned mode, struct object_id *oid, static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix, struct child_process *child) { - char tmpdir[PATH_MAX]; struct strbuf info = STRBUF_INIT, lpath = STRBUF_INIT; struct strbuf rpath = STRBUF_INIT, buf = STRBUF_INIT; struct strbuf ldir = STRBUF_INIT, rdir = STRBUF_INIT; struct strbuf wtdir = STRBUF_INIT; - char *lbase_dir, *rbase_dir; + struct strbuf tmpdir = STRBUF_INIT; + char *lbase_dir = NULL, *rbase_dir = NULL; size_t ldir_len, rdir_len, wtdir_len; const char *workdir, *tmp; int ret = 0, i; - FILE *fp; + FILE *fp = NULL; struct hashmap working_tree_dups = HASHMAP_INIT(working_tree_entry_cmp, NULL); struct hashmap submodules = HASHMAP_INIT(pair_cmp, NULL); @@ -351,7 +341,7 @@ static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix, struct pair_entry *entry; struct index_state wtindex; struct checkout lstate, rstate; - int rc, flags = RUN_GIT_CMD, err = 0; + int flags = RUN_GIT_CMD, err = 0; const char *helper_argv[] = { "difftool--helper", NULL, NULL, NULL }; struct hashmap wt_modified, tmp_modified; int indices_loaded = 0; @@ -360,11 +350,15 @@ static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix, /* Setup temp directories */ tmp = getenv("TMPDIR"); - xsnprintf(tmpdir, sizeof(tmpdir), "%s/git-difftool.XXXXXX", tmp ? tmp : "/tmp"); - if (!mkdtemp(tmpdir)) - return error("could not create '%s'", tmpdir); - strbuf_addf(&ldir, "%s/left/", tmpdir); - strbuf_addf(&rdir, "%s/right/", tmpdir); + strbuf_add_absolute_path(&tmpdir, tmp ? tmp : "/tmp"); + strbuf_trim_trailing_dir_sep(&tmpdir); + strbuf_addstr(&tmpdir, "/git-difftool.XXXXXX"); + if (!mkdtemp(tmpdir.buf)) { + ret = error("could not create '%s'", tmpdir.buf); + goto finish; + } + strbuf_addf(&ldir, "%s/left/", tmpdir.buf); + strbuf_addf(&rdir, "%s/right/", tmpdir.buf); strbuf_addstr(&wtdir, workdir); if (!wtdir.len || !is_dir_sep(wtdir.buf[wtdir.len - 1])) strbuf_addch(&wtdir, '/'); @@ -580,7 +574,7 @@ static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix, flags = 0; } else setenv("GIT_DIFFTOOL_DIRDIFF", "true", 1); - rc = run_command_v_opt(helper_argv, flags); + ret = run_command_v_opt(helper_argv, flags); /* TODO: audit for interaction with sparse-index. */ ensure_full_index(&wtindex); @@ -614,7 +608,7 @@ static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix, if (!indices_loaded) { struct lock_file lock = LOCK_INIT; strbuf_reset(&buf); - strbuf_addf(&buf, "%s/wtindex", tmpdir); + strbuf_addf(&buf, "%s/wtindex", tmpdir.buf); if (hold_lock_file_for_update(&lock, buf.buf, 0) < 0 || write_locked_index(&wtindex, &lock, COMMIT_LOCK)) { ret = error("could not write %s", buf.buf); @@ -644,11 +638,14 @@ static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix, } if (err) { - warning(_("temporary files exist in '%s'."), tmpdir); + warning(_("temporary files exist in '%s'."), tmpdir.buf); warning(_("you may want to cleanup or recover these.")); - exit(1); - } else - exit_cleanup(tmpdir, rc); + ret = 1; + } else { + remove_dir_recursively(&tmpdir, 0); + if (ret) + warning(_("failed: %d"), ret); + } finish: if (fp) @@ -660,6 +657,7 @@ static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix, strbuf_release(&rdir); strbuf_release(&wtdir); strbuf_release(&buf); + strbuf_release(&tmpdir); return ret; } diff --git a/t/t7800-difftool.sh b/t/t7800-difftool.sh index 07a52fb8e1..0670b617b4 100755 --- a/t/t7800-difftool.sh +++ b/t/t7800-difftool.sh @@ -453,6 +453,13 @@ run_dir_diff_test 'difftool --dir-diff' ' grep "^file$" output ' +run_dir_diff_test 'difftool --dir-diff avoids repeated slashes in TMPDIR' ' + TMPDIR="${TMPDIR:-/tmp}////" \ + git difftool --dir-diff $symlinks --extcmd echo branch >output && + grep -v // output >actual && + test_line_count = 1 actual +' + run_dir_diff_test 'difftool --dir-diff ignores --prompt' ' git difftool --dir-diff $symlinks --prompt --extcmd ls branch >output && grep "^sub$" output && -- 2.33.0.372.g520515731c ^ permalink raw reply related [flat|nested] 10+ messages in thread
* [PATCH v4 3/3] difftool: add a missing space to the run_dir_diff() comments 2021-09-19 20:38 [PATCH v4 0/3] difftool dir-diff symlink bug fix and cleanup patches David Aguilar 2021-09-19 20:38 ` [PATCH v4 1/3] difftool: fix symlink-file writing in dir-diff mode David Aguilar 2021-09-19 20:38 ` [PATCH v4 2/3] difftool: use a strbuf to create a tmpdir path without repeated slashes David Aguilar @ 2021-09-19 20:38 ` David Aguilar 2021-09-20 18:39 ` [PATCH v4 0/3] difftool dir-diff symlink bug fix and cleanup patches Junio C Hamano 3 siblings, 0 replies; 10+ messages in thread From: David Aguilar @ 2021-09-19 20:38 UTC (permalink / raw) To: Junio C Hamano Cc: Git Mailing List, Johannes Schindelin, Alan Blotz, Đoàn Trần Công Danh, Ævar Arnfjörð Bjarmason, Jeff King Signed-off-by: David Aguilar <davvid@gmail.com> --- builtin/difftool.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/builtin/difftool.c b/builtin/difftool.c index daa438be09..e225974a2b 100644 --- a/builtin/difftool.c +++ b/builtin/difftool.c @@ -549,7 +549,7 @@ static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix, } /* - * Symbolic links require special treatment.The standard "git diff" + * Symbolic links require special treatment. The standard "git diff" * shows only the link itself, not the contents of the link target. * This loop replicates that behavior. */ -- 2.33.0.720.g5b0b3ce580 ^ permalink raw reply related [flat|nested] 10+ messages in thread
* Re: [PATCH v4 0/3] difftool dir-diff symlink bug fix and cleanup patches 2021-09-19 20:38 [PATCH v4 0/3] difftool dir-diff symlink bug fix and cleanup patches David Aguilar ` (2 preceding siblings ...) 2021-09-19 20:38 ` [PATCH v4 3/3] difftool: add a missing space to the run_dir_diff() comments David Aguilar @ 2021-09-20 18:39 ` Junio C Hamano 2021-09-20 21:43 ` David Aguilar 3 siblings, 1 reply; 10+ messages in thread From: Junio C Hamano @ 2021-09-20 18:39 UTC (permalink / raw) To: David Aguilar Cc: Git Mailing List, Johannes Schindelin, Alan Blotz, Đoàn Trần Công Danh, Ævar Arnfjörð Bjarmason, Jeff King David Aguilar <davvid@gmail.com> writes: > This patch series fixes a regression in difftool that can lead to data loss. > The symlink-file writing in difftool's dir-diff mode has been fixed to no > longer write-through to the symlink targets. v4 with no backreference? Do you have a message-id for the previous three rounds handy? > Please consider patching older Git versions with the fix from 1/3. meaing 1/3 would be done on top of maint (v2.33.0), and the other two can be on a separate branch that starts on a commit that is a merge of the 1/3's branch into 'master'? Thanks. ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH v4 0/3] difftool dir-diff symlink bug fix and cleanup patches 2021-09-20 18:39 ` [PATCH v4 0/3] difftool dir-diff symlink bug fix and cleanup patches Junio C Hamano @ 2021-09-20 21:43 ` David Aguilar 2021-09-22 18:43 ` Junio C Hamano 0 siblings, 1 reply; 10+ messages in thread From: David Aguilar @ 2021-09-20 21:43 UTC (permalink / raw) To: Junio C Hamano Cc: Git Mailing List, Johannes Schindelin, Alan Blotz, Đoàn Trần Công Danh, Ævar Arnfjörð Bjarmason, Jeff King On Mon, Sep 20, 2021 at 11:39 AM Junio C Hamano <gitster@pobox.com> wrote: > > David Aguilar <davvid@gmail.com> writes: > > > This patch series fixes a regression in difftool that can lead to data loss. > > The symlink-file writing in difftool's dir-diff mode has been fixed to no > > longer write-through to the symlink targets. > > v4 with no backreference? Do you have a message-id for the previous > three rounds handy? <20210919015729.98323-4-davvid@gmail.com> v1 was dead on arrival so v2 was really the first. There was no v3 -- a different patch in the series went to v3 so I bumped the entire series to v4. > > Please consider patching older Git versions with the fix from 1/3. > > meaing 1/3 would be done on top of maint (v2.33.0), and the other > two can be on a separate branch that starts on a commit that is a > merge of the 1/3's branch into 'master'? > > Thanks. Thanks. Patch 3/3 seems trivially correct so I won't resend that either. Ævar had notes about 2/3 which can be split off to a separate topic, so that's the only one I'll plan to resend all by itself --in-reply-to that thread. I see that it's already in "seen". I can send a replacement patch shortly if that's not too much trouble; dropping "strbuf" from the subject line in the commit message and the note about the test would be good to cleanup. The strbuf leaks will be addressed in the replacement patch. -- David ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH v4 0/3] difftool dir-diff symlink bug fix and cleanup patches 2021-09-20 21:43 ` David Aguilar @ 2021-09-22 18:43 ` Junio C Hamano 0 siblings, 0 replies; 10+ messages in thread From: Junio C Hamano @ 2021-09-22 18:43 UTC (permalink / raw) To: David Aguilar Cc: Git Mailing List, Johannes Schindelin, Alan Blotz, Đoàn Trần Công Danh, Ævar Arnfjörð Bjarmason, Jeff King David Aguilar <davvid@gmail.com> writes: > Thanks. Patch 3/3 seems trivially correct so I won't resend that either. > > Ævar had notes about 2/3 which can be split off to a separate topic, > so that's the only one I'll plan to resend all by itself --in-reply-to > that thread. Please don't do this. Your topic is not the only one I am looking at, and being able to find the whole thing together is always more efficient than having to go back, re-read the discussion and pick the latest iteration of each step individually (which will not work if the topic needs reordering of the patches in it anyway). > I see that it's already in "seen". I can send a replacement patch > shortly ... Please do not read anything in a topic being (or not being, for that matter) "seen". It means "the maintainer has seen it and thought it might be interesting at one point of time in the past" and nothing more. It certainly does not mean the maintainer is keeping track of how the topic is evolving and knows which piece will be replaced and which piece is already done. Thanks. ^ permalink raw reply [flat|nested] 10+ messages in thread
end of thread, other threads:[~2021-09-22 18:43 UTC | newest] Thread overview: 10+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2021-09-19 20:38 [PATCH v4 0/3] difftool dir-diff symlink bug fix and cleanup patches David Aguilar 2021-09-19 20:38 ` [PATCH v4 1/3] difftool: fix symlink-file writing in dir-diff mode David Aguilar 2021-09-20 7:59 ` Ævar Arnfjörð Bjarmason 2021-09-19 20:38 ` [PATCH v4 2/3] difftool: use a strbuf to create a tmpdir path without repeated slashes David Aguilar 2021-09-20 5:40 ` Eric Sunshine 2021-09-20 22:08 ` [PATCH v5] difftool: " David Aguilar 2021-09-19 20:38 ` [PATCH v4 3/3] difftool: add a missing space to the run_dir_diff() comments David Aguilar 2021-09-20 18:39 ` [PATCH v4 0/3] difftool dir-diff symlink bug fix and cleanup patches Junio C Hamano 2021-09-20 21:43 ` David Aguilar 2021-09-22 18:43 ` Junio C Hamano
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