diff: clear emitted_symbols flag after use
There's an odd bug when "log --color-moved" is used with the combination
of "--cc --stat -p": the stat for merge commits is erroneously shown
with the diff of the _next_ commit.
The included test demonstrates the issue. Our history looks something
like this:
A-B-M--D
\ /
C
When we run "git log --cc --stat -p --color-moved" starting at D, we get
this sequence of events:
1. The diff for D is using -p, so diff_flush() calls into
diff_flush_patch_all_file_pairs(). There we see that o->color_moved
is in effect, so we point o->emitted_symbols to a static local
struct, causing diff_flush_patch() to queue the symbols instead of
actually writing them out.
We then do our move detection, emit the symbols, and clear the
struct. But we leave o->emitted_symbols pointing to our struct.
2. Next we compute the diff for M. This is a merge, so we use the
combined diff code. In find_paths_generic(), we compute the
pairwise diff between each commit and its parent. Normally this is
done with DIFF_FORMAT_NO_OUTPUT, since we're just looking for
intersecting paths. But since "--stat --cc" shows the first-parent
stat, and since we're computing that diff anyway, we enable
DIFF_FORMAT_DIFFSTAT for the first parent. This outputs the stat
information immediately, saving us from running a separate
first-parent diff later.
But where does that output go? Normally it goes directly to stdout,
but because o->emitted_symbols is set, we queue it. As a result, we
don't actually print the diffstat for the merge commit (yet), which
is wrong.
3. Next we compute the diff for C. We're actually showing a patch
again, so we end up in diff_flush_patch_all_file_pairs(), but this
time we have the queued stat from step 2 waiting in our struct.
We add new elements to it for C's diff, and then flush the whole
thing. And we see the diffstat from M as part of C's diff, which is
wrong.
So triggering the bug really does require the combination of all of
those options.
To fix it, we can simply restore o->emitted_symbols to NULL after
flushing it, so that it does not affect anything outside of
diff_flush_patch_all_file_pairs(). This intuitively makes sense, since
nobody outside of that function is going to bother flushing it, so we
would not want them to write to it either.
In fact, we could take this a step further and turn the local "esm"
struct into a non-static variable that goes away after the function
ends. However, since it contains a dynamically sized array, we benefit
from amortizing the cost of allocations over many calls. So we'll leave
it as static to retain that benefit.
But let's push the zero-ing of esm.nr into the conditional for "if
(o->emitted_symbols)" to make it clear that we do not expect esm to hold
any values if we did not just try to use it. With the code as it is
written now, if we did encounter such a case (which I think would be a
bug), we'd silently leak those values without even bothering to display
them. With this change, we'd at least eventually show them, and somebody
would notice.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-24 13:32:41 +01:00
|
|
|
#!/bin/sh
|
|
|
|
|
|
|
|
|
|
test_description='test combined/stat/moved interaction'
|
2020-11-19 00:44:27 +01:00
|
|
|
GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
|
tests: mark tests relying on the current default for `init.defaultBranch`
In addition to the manual adjustment to let the `linux-gcc` CI job run
the test suite with `master` and then with `main`, this patch makes sure
that GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME is set in all test scripts
that currently rely on the initial branch name being `master by default.
To determine which test scripts to mark up, the first step was to
force-set the default branch name to `master` in
- all test scripts that contain the keyword `master`,
- t4211, which expects `t/t4211/history.export` with a hard-coded ref to
initialize the default branch,
- t5560 because it sources `t/t556x_common` which uses `master`,
- t8002 and t8012 because both source `t/annotate-tests.sh` which also
uses `master`)
This trick was performed by this command:
$ sed -i '/^ *\. \.\/\(test-lib\|lib-\(bash\|cvs\|git-svn\)\|gitweb-lib\)\.sh$/i\
GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=master\
export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME\
' $(git grep -l master t/t[0-9]*.sh) \
t/t4211*.sh t/t5560*.sh t/t8002*.sh t/t8012*.sh
After that, careful, manual inspection revealed that some of the test
scripts containing the needle `master` do not actually rely on a
specific default branch name: either they mention `master` only in a
comment, or they initialize that branch specificially, or they do not
actually refer to the current default branch. Therefore, the
aforementioned modification was undone in those test scripts thusly:
$ git checkout HEAD -- \
t/t0027-auto-crlf.sh t/t0060-path-utils.sh \
t/t1011-read-tree-sparse-checkout.sh \
t/t1305-config-include.sh t/t1309-early-config.sh \
t/t1402-check-ref-format.sh t/t1450-fsck.sh \
t/t2024-checkout-dwim.sh \
t/t2106-update-index-assume-unchanged.sh \
t/t3040-subprojects-basic.sh t/t3301-notes.sh \
t/t3308-notes-merge.sh t/t3423-rebase-reword.sh \
t/t3436-rebase-more-options.sh \
t/t4015-diff-whitespace.sh t/t4257-am-interactive.sh \
t/t5323-pack-redundant.sh t/t5401-update-hooks.sh \
t/t5511-refspec.sh t/t5526-fetch-submodules.sh \
t/t5529-push-errors.sh t/t5530-upload-pack-error.sh \
t/t5548-push-porcelain.sh \
t/t5552-skipping-fetch-negotiator.sh \
t/t5572-pull-submodule.sh t/t5608-clone-2gb.sh \
t/t5614-clone-submodules-shallow.sh \
t/t7508-status.sh t/t7606-merge-custom.sh \
t/t9302-fast-import-unpack-limit.sh
We excluded one set of test scripts in these commands, though: the range
of `git p4` tests. The reason? `git p4` stores the (foreign) remote
branch in the branch called `p4/master`, which is obviously not the
default branch. Manual analysis revealed that only five of these tests
actually require a specific default branch name to pass; They were
modified thusly:
$ sed -i '/^ *\. \.\/lib-git-p4\.sh$/i\
GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=master\
export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME\
' t/t980[0167]*.sh t/t9811*.sh
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-19 00:44:19 +01:00
|
|
|
export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
|
|
|
|
|
|
diff: clear emitted_symbols flag after use
There's an odd bug when "log --color-moved" is used with the combination
of "--cc --stat -p": the stat for merge commits is erroneously shown
with the diff of the _next_ commit.
The included test demonstrates the issue. Our history looks something
like this:
A-B-M--D
\ /
C
When we run "git log --cc --stat -p --color-moved" starting at D, we get
this sequence of events:
1. The diff for D is using -p, so diff_flush() calls into
diff_flush_patch_all_file_pairs(). There we see that o->color_moved
is in effect, so we point o->emitted_symbols to a static local
struct, causing diff_flush_patch() to queue the symbols instead of
actually writing them out.
We then do our move detection, emit the symbols, and clear the
struct. But we leave o->emitted_symbols pointing to our struct.
2. Next we compute the diff for M. This is a merge, so we use the
combined diff code. In find_paths_generic(), we compute the
pairwise diff between each commit and its parent. Normally this is
done with DIFF_FORMAT_NO_OUTPUT, since we're just looking for
intersecting paths. But since "--stat --cc" shows the first-parent
stat, and since we're computing that diff anyway, we enable
DIFF_FORMAT_DIFFSTAT for the first parent. This outputs the stat
information immediately, saving us from running a separate
first-parent diff later.
But where does that output go? Normally it goes directly to stdout,
but because o->emitted_symbols is set, we queue it. As a result, we
don't actually print the diffstat for the merge commit (yet), which
is wrong.
3. Next we compute the diff for C. We're actually showing a patch
again, so we end up in diff_flush_patch_all_file_pairs(), but this
time we have the queued stat from step 2 waiting in our struct.
We add new elements to it for C's diff, and then flush the whole
thing. And we see the diffstat from M as part of C's diff, which is
wrong.
So triggering the bug really does require the combination of all of
those options.
To fix it, we can simply restore o->emitted_symbols to NULL after
flushing it, so that it does not affect anything outside of
diff_flush_patch_all_file_pairs(). This intuitively makes sense, since
nobody outside of that function is going to bother flushing it, so we
would not want them to write to it either.
In fact, we could take this a step further and turn the local "esm"
struct into a non-static variable that goes away after the function
ends. However, since it contains a dynamically sized array, we benefit
from amortizing the cost of allocations over many calls. So we'll leave
it as static to retain that benefit.
But let's push the zero-ing of esm.nr into the conditional for "if
(o->emitted_symbols)" to make it clear that we do not expect esm to hold
any values if we did not just try to use it. With the code as it is
written now, if we did encounter such a case (which I think would be a
bug), we'd silently leak those values without even bothering to display
them. With this change, we'd at least eventually show them, and somebody
would notice.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-24 13:32:41 +01:00
|
|
|
. ./test-lib.sh
|
|
|
|
|
|
|
|
|
|
# This test covers a weird 3-way interaction between "--cc -p", which will run
|
|
|
|
|
# the combined diff code, along with "--stat", which will be computed as a
|
|
|
|
|
# first-parent stat during the combined diff, and "--color-moved", which
|
|
|
|
|
# enables the emitted_symbols list to store the diff in memory.
|
|
|
|
|
|
|
|
|
|
test_expect_success 'set up history with a merge' '
|
|
|
|
|
test_commit A &&
|
|
|
|
|
test_commit B &&
|
|
|
|
|
git checkout -b side HEAD^ &&
|
|
|
|
|
test_commit C &&
|
2020-11-19 00:44:27 +01:00
|
|
|
git merge -m M main &&
|
diff: clear emitted_symbols flag after use
There's an odd bug when "log --color-moved" is used with the combination
of "--cc --stat -p": the stat for merge commits is erroneously shown
with the diff of the _next_ commit.
The included test demonstrates the issue. Our history looks something
like this:
A-B-M--D
\ /
C
When we run "git log --cc --stat -p --color-moved" starting at D, we get
this sequence of events:
1. The diff for D is using -p, so diff_flush() calls into
diff_flush_patch_all_file_pairs(). There we see that o->color_moved
is in effect, so we point o->emitted_symbols to a static local
struct, causing diff_flush_patch() to queue the symbols instead of
actually writing them out.
We then do our move detection, emit the symbols, and clear the
struct. But we leave o->emitted_symbols pointing to our struct.
2. Next we compute the diff for M. This is a merge, so we use the
combined diff code. In find_paths_generic(), we compute the
pairwise diff between each commit and its parent. Normally this is
done with DIFF_FORMAT_NO_OUTPUT, since we're just looking for
intersecting paths. But since "--stat --cc" shows the first-parent
stat, and since we're computing that diff anyway, we enable
DIFF_FORMAT_DIFFSTAT for the first parent. This outputs the stat
information immediately, saving us from running a separate
first-parent diff later.
But where does that output go? Normally it goes directly to stdout,
but because o->emitted_symbols is set, we queue it. As a result, we
don't actually print the diffstat for the merge commit (yet), which
is wrong.
3. Next we compute the diff for C. We're actually showing a patch
again, so we end up in diff_flush_patch_all_file_pairs(), but this
time we have the queued stat from step 2 waiting in our struct.
We add new elements to it for C's diff, and then flush the whole
thing. And we see the diffstat from M as part of C's diff, which is
wrong.
So triggering the bug really does require the combination of all of
those options.
To fix it, we can simply restore o->emitted_symbols to NULL after
flushing it, so that it does not affect anything outside of
diff_flush_patch_all_file_pairs(). This intuitively makes sense, since
nobody outside of that function is going to bother flushing it, so we
would not want them to write to it either.
In fact, we could take this a step further and turn the local "esm"
struct into a non-static variable that goes away after the function
ends. However, since it contains a dynamically sized array, we benefit
from amortizing the cost of allocations over many calls. So we'll leave
it as static to retain that benefit.
But let's push the zero-ing of esm.nr into the conditional for "if
(o->emitted_symbols)" to make it clear that we do not expect esm to hold
any values if we did not just try to use it. With the code as it is
written now, if we did encounter such a case (which I think would be a
bug), we'd silently leak those values without even bothering to display
them. With this change, we'd at least eventually show them, and somebody
would notice.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-24 13:32:41 +01:00
|
|
|
test_commit D
|
|
|
|
|
'
|
|
|
|
|
|
|
|
|
|
test_expect_success 'log --cc -p --stat --color-moved' '
|
2019-12-21 20:49:18 +01:00
|
|
|
cat >expect <<-EOF &&
|
diff: clear emitted_symbols flag after use
There's an odd bug when "log --color-moved" is used with the combination
of "--cc --stat -p": the stat for merge commits is erroneously shown
with the diff of the _next_ commit.
The included test demonstrates the issue. Our history looks something
like this:
A-B-M--D
\ /
C
When we run "git log --cc --stat -p --color-moved" starting at D, we get
this sequence of events:
1. The diff for D is using -p, so diff_flush() calls into
diff_flush_patch_all_file_pairs(). There we see that o->color_moved
is in effect, so we point o->emitted_symbols to a static local
struct, causing diff_flush_patch() to queue the symbols instead of
actually writing them out.
We then do our move detection, emit the symbols, and clear the
struct. But we leave o->emitted_symbols pointing to our struct.
2. Next we compute the diff for M. This is a merge, so we use the
combined diff code. In find_paths_generic(), we compute the
pairwise diff between each commit and its parent. Normally this is
done with DIFF_FORMAT_NO_OUTPUT, since we're just looking for
intersecting paths. But since "--stat --cc" shows the first-parent
stat, and since we're computing that diff anyway, we enable
DIFF_FORMAT_DIFFSTAT for the first parent. This outputs the stat
information immediately, saving us from running a separate
first-parent diff later.
But where does that output go? Normally it goes directly to stdout,
but because o->emitted_symbols is set, we queue it. As a result, we
don't actually print the diffstat for the merge commit (yet), which
is wrong.
3. Next we compute the diff for C. We're actually showing a patch
again, so we end up in diff_flush_patch_all_file_pairs(), but this
time we have the queued stat from step 2 waiting in our struct.
We add new elements to it for C's diff, and then flush the whole
thing. And we see the diffstat from M as part of C's diff, which is
wrong.
So triggering the bug really does require the combination of all of
those options.
To fix it, we can simply restore o->emitted_symbols to NULL after
flushing it, so that it does not affect anything outside of
diff_flush_patch_all_file_pairs(). This intuitively makes sense, since
nobody outside of that function is going to bother flushing it, so we
would not want them to write to it either.
In fact, we could take this a step further and turn the local "esm"
struct into a non-static variable that goes away after the function
ends. However, since it contains a dynamically sized array, we benefit
from amortizing the cost of allocations over many calls. So we'll leave
it as static to retain that benefit.
But let's push the zero-ing of esm.nr into the conditional for "if
(o->emitted_symbols)" to make it clear that we do not expect esm to hold
any values if we did not just try to use it. With the code as it is
written now, if we did encounter such a case (which I think would be a
bug), we'd silently leak those values without even bothering to display
them. With this change, we'd at least eventually show them, and somebody
would notice.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-24 13:32:41 +01:00
|
|
|
commit D
|
|
|
|
|
---
|
|
|
|
|
D.t | 1 +
|
|
|
|
|
1 file changed, 1 insertion(+)
|
|
|
|
|
|
|
|
|
|
diff --git a/D.t b/D.t
|
|
|
|
|
new file mode 100644
|
2019-12-21 20:49:18 +01:00
|
|
|
index 0000000..$(git rev-parse --short D:D.t)
|
diff: clear emitted_symbols flag after use
There's an odd bug when "log --color-moved" is used with the combination
of "--cc --stat -p": the stat for merge commits is erroneously shown
with the diff of the _next_ commit.
The included test demonstrates the issue. Our history looks something
like this:
A-B-M--D
\ /
C
When we run "git log --cc --stat -p --color-moved" starting at D, we get
this sequence of events:
1. The diff for D is using -p, so diff_flush() calls into
diff_flush_patch_all_file_pairs(). There we see that o->color_moved
is in effect, so we point o->emitted_symbols to a static local
struct, causing diff_flush_patch() to queue the symbols instead of
actually writing them out.
We then do our move detection, emit the symbols, and clear the
struct. But we leave o->emitted_symbols pointing to our struct.
2. Next we compute the diff for M. This is a merge, so we use the
combined diff code. In find_paths_generic(), we compute the
pairwise diff between each commit and its parent. Normally this is
done with DIFF_FORMAT_NO_OUTPUT, since we're just looking for
intersecting paths. But since "--stat --cc" shows the first-parent
stat, and since we're computing that diff anyway, we enable
DIFF_FORMAT_DIFFSTAT for the first parent. This outputs the stat
information immediately, saving us from running a separate
first-parent diff later.
But where does that output go? Normally it goes directly to stdout,
but because o->emitted_symbols is set, we queue it. As a result, we
don't actually print the diffstat for the merge commit (yet), which
is wrong.
3. Next we compute the diff for C. We're actually showing a patch
again, so we end up in diff_flush_patch_all_file_pairs(), but this
time we have the queued stat from step 2 waiting in our struct.
We add new elements to it for C's diff, and then flush the whole
thing. And we see the diffstat from M as part of C's diff, which is
wrong.
So triggering the bug really does require the combination of all of
those options.
To fix it, we can simply restore o->emitted_symbols to NULL after
flushing it, so that it does not affect anything outside of
diff_flush_patch_all_file_pairs(). This intuitively makes sense, since
nobody outside of that function is going to bother flushing it, so we
would not want them to write to it either.
In fact, we could take this a step further and turn the local "esm"
struct into a non-static variable that goes away after the function
ends. However, since it contains a dynamically sized array, we benefit
from amortizing the cost of allocations over many calls. So we'll leave
it as static to retain that benefit.
But let's push the zero-ing of esm.nr into the conditional for "if
(o->emitted_symbols)" to make it clear that we do not expect esm to hold
any values if we did not just try to use it. With the code as it is
written now, if we did encounter such a case (which I think would be a
bug), we'd silently leak those values without even bothering to display
them. With this change, we'd at least eventually show them, and somebody
would notice.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-24 13:32:41 +01:00
|
|
|
--- /dev/null
|
|
|
|
|
+++ b/D.t
|
|
|
|
|
@@ -0,0 +1 @@
|
|
|
|
|
+D
|
|
|
|
|
commit M
|
|
|
|
|
|
|
|
|
|
B.t | 1 +
|
|
|
|
|
1 file changed, 1 insertion(+)
|
|
|
|
|
commit C
|
|
|
|
|
---
|
|
|
|
|
C.t | 1 +
|
|
|
|
|
1 file changed, 1 insertion(+)
|
|
|
|
|
|
|
|
|
|
diff --git a/C.t b/C.t
|
|
|
|
|
new file mode 100644
|
2019-12-21 20:49:18 +01:00
|
|
|
index 0000000..$(git rev-parse --short C:C.t)
|
diff: clear emitted_symbols flag after use
There's an odd bug when "log --color-moved" is used with the combination
of "--cc --stat -p": the stat for merge commits is erroneously shown
with the diff of the _next_ commit.
The included test demonstrates the issue. Our history looks something
like this:
A-B-M--D
\ /
C
When we run "git log --cc --stat -p --color-moved" starting at D, we get
this sequence of events:
1. The diff for D is using -p, so diff_flush() calls into
diff_flush_patch_all_file_pairs(). There we see that o->color_moved
is in effect, so we point o->emitted_symbols to a static local
struct, causing diff_flush_patch() to queue the symbols instead of
actually writing them out.
We then do our move detection, emit the symbols, and clear the
struct. But we leave o->emitted_symbols pointing to our struct.
2. Next we compute the diff for M. This is a merge, so we use the
combined diff code. In find_paths_generic(), we compute the
pairwise diff between each commit and its parent. Normally this is
done with DIFF_FORMAT_NO_OUTPUT, since we're just looking for
intersecting paths. But since "--stat --cc" shows the first-parent
stat, and since we're computing that diff anyway, we enable
DIFF_FORMAT_DIFFSTAT for the first parent. This outputs the stat
information immediately, saving us from running a separate
first-parent diff later.
But where does that output go? Normally it goes directly to stdout,
but because o->emitted_symbols is set, we queue it. As a result, we
don't actually print the diffstat for the merge commit (yet), which
is wrong.
3. Next we compute the diff for C. We're actually showing a patch
again, so we end up in diff_flush_patch_all_file_pairs(), but this
time we have the queued stat from step 2 waiting in our struct.
We add new elements to it for C's diff, and then flush the whole
thing. And we see the diffstat from M as part of C's diff, which is
wrong.
So triggering the bug really does require the combination of all of
those options.
To fix it, we can simply restore o->emitted_symbols to NULL after
flushing it, so that it does not affect anything outside of
diff_flush_patch_all_file_pairs(). This intuitively makes sense, since
nobody outside of that function is going to bother flushing it, so we
would not want them to write to it either.
In fact, we could take this a step further and turn the local "esm"
struct into a non-static variable that goes away after the function
ends. However, since it contains a dynamically sized array, we benefit
from amortizing the cost of allocations over many calls. So we'll leave
it as static to retain that benefit.
But let's push the zero-ing of esm.nr into the conditional for "if
(o->emitted_symbols)" to make it clear that we do not expect esm to hold
any values if we did not just try to use it. With the code as it is
written now, if we did encounter such a case (which I think would be a
bug), we'd silently leak those values without even bothering to display
them. With this change, we'd at least eventually show them, and somebody
would notice.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-24 13:32:41 +01:00
|
|
|
--- /dev/null
|
|
|
|
|
+++ b/C.t
|
|
|
|
|
@@ -0,0 +1 @@
|
|
|
|
|
+C
|
|
|
|
|
commit B
|
|
|
|
|
---
|
|
|
|
|
B.t | 1 +
|
|
|
|
|
1 file changed, 1 insertion(+)
|
|
|
|
|
|
|
|
|
|
diff --git a/B.t b/B.t
|
|
|
|
|
new file mode 100644
|
2019-12-21 20:49:18 +01:00
|
|
|
index 0000000..$(git rev-parse --short B:B.t)
|
diff: clear emitted_symbols flag after use
There's an odd bug when "log --color-moved" is used with the combination
of "--cc --stat -p": the stat for merge commits is erroneously shown
with the diff of the _next_ commit.
The included test demonstrates the issue. Our history looks something
like this:
A-B-M--D
\ /
C
When we run "git log --cc --stat -p --color-moved" starting at D, we get
this sequence of events:
1. The diff for D is using -p, so diff_flush() calls into
diff_flush_patch_all_file_pairs(). There we see that o->color_moved
is in effect, so we point o->emitted_symbols to a static local
struct, causing diff_flush_patch() to queue the symbols instead of
actually writing them out.
We then do our move detection, emit the symbols, and clear the
struct. But we leave o->emitted_symbols pointing to our struct.
2. Next we compute the diff for M. This is a merge, so we use the
combined diff code. In find_paths_generic(), we compute the
pairwise diff between each commit and its parent. Normally this is
done with DIFF_FORMAT_NO_OUTPUT, since we're just looking for
intersecting paths. But since "--stat --cc" shows the first-parent
stat, and since we're computing that diff anyway, we enable
DIFF_FORMAT_DIFFSTAT for the first parent. This outputs the stat
information immediately, saving us from running a separate
first-parent diff later.
But where does that output go? Normally it goes directly to stdout,
but because o->emitted_symbols is set, we queue it. As a result, we
don't actually print the diffstat for the merge commit (yet), which
is wrong.
3. Next we compute the diff for C. We're actually showing a patch
again, so we end up in diff_flush_patch_all_file_pairs(), but this
time we have the queued stat from step 2 waiting in our struct.
We add new elements to it for C's diff, and then flush the whole
thing. And we see the diffstat from M as part of C's diff, which is
wrong.
So triggering the bug really does require the combination of all of
those options.
To fix it, we can simply restore o->emitted_symbols to NULL after
flushing it, so that it does not affect anything outside of
diff_flush_patch_all_file_pairs(). This intuitively makes sense, since
nobody outside of that function is going to bother flushing it, so we
would not want them to write to it either.
In fact, we could take this a step further and turn the local "esm"
struct into a non-static variable that goes away after the function
ends. However, since it contains a dynamically sized array, we benefit
from amortizing the cost of allocations over many calls. So we'll leave
it as static to retain that benefit.
But let's push the zero-ing of esm.nr into the conditional for "if
(o->emitted_symbols)" to make it clear that we do not expect esm to hold
any values if we did not just try to use it. With the code as it is
written now, if we did encounter such a case (which I think would be a
bug), we'd silently leak those values without even bothering to display
them. With this change, we'd at least eventually show them, and somebody
would notice.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-24 13:32:41 +01:00
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--- /dev/null
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|
|
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|
+++ b/B.t
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|
|
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@@ -0,0 +1 @@
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+B
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|
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commit A
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---
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|
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A.t | 1 +
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1 file changed, 1 insertion(+)
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diff --git a/A.t b/A.t
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new file mode 100644
|
2019-12-21 20:49:18 +01:00
|
|
|
index 0000000..$(git rev-parse --short A:A.t)
|
diff: clear emitted_symbols flag after use
There's an odd bug when "log --color-moved" is used with the combination
of "--cc --stat -p": the stat for merge commits is erroneously shown
with the diff of the _next_ commit.
The included test demonstrates the issue. Our history looks something
like this:
A-B-M--D
\ /
C
When we run "git log --cc --stat -p --color-moved" starting at D, we get
this sequence of events:
1. The diff for D is using -p, so diff_flush() calls into
diff_flush_patch_all_file_pairs(). There we see that o->color_moved
is in effect, so we point o->emitted_symbols to a static local
struct, causing diff_flush_patch() to queue the symbols instead of
actually writing them out.
We then do our move detection, emit the symbols, and clear the
struct. But we leave o->emitted_symbols pointing to our struct.
2. Next we compute the diff for M. This is a merge, so we use the
combined diff code. In find_paths_generic(), we compute the
pairwise diff between each commit and its parent. Normally this is
done with DIFF_FORMAT_NO_OUTPUT, since we're just looking for
intersecting paths. But since "--stat --cc" shows the first-parent
stat, and since we're computing that diff anyway, we enable
DIFF_FORMAT_DIFFSTAT for the first parent. This outputs the stat
information immediately, saving us from running a separate
first-parent diff later.
But where does that output go? Normally it goes directly to stdout,
but because o->emitted_symbols is set, we queue it. As a result, we
don't actually print the diffstat for the merge commit (yet), which
is wrong.
3. Next we compute the diff for C. We're actually showing a patch
again, so we end up in diff_flush_patch_all_file_pairs(), but this
time we have the queued stat from step 2 waiting in our struct.
We add new elements to it for C's diff, and then flush the whole
thing. And we see the diffstat from M as part of C's diff, which is
wrong.
So triggering the bug really does require the combination of all of
those options.
To fix it, we can simply restore o->emitted_symbols to NULL after
flushing it, so that it does not affect anything outside of
diff_flush_patch_all_file_pairs(). This intuitively makes sense, since
nobody outside of that function is going to bother flushing it, so we
would not want them to write to it either.
In fact, we could take this a step further and turn the local "esm"
struct into a non-static variable that goes away after the function
ends. However, since it contains a dynamically sized array, we benefit
from amortizing the cost of allocations over many calls. So we'll leave
it as static to retain that benefit.
But let's push the zero-ing of esm.nr into the conditional for "if
(o->emitted_symbols)" to make it clear that we do not expect esm to hold
any values if we did not just try to use it. With the code as it is
written now, if we did encounter such a case (which I think would be a
bug), we'd silently leak those values without even bothering to display
them. With this change, we'd at least eventually show them, and somebody
would notice.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-24 13:32:41 +01:00
|
|
|
--- /dev/null
|
|
|
|
|
+++ b/A.t
|
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@@ -0,0 +1 @@
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+A
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EOF
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git log --format="commit %s" --cc -p --stat --color-moved >actual &&
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test_cmp expect actual
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'
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test_done
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