WIP: Address getenv() issues #2019
Open
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
dscho
force-pushed
the
getenv-fixes
branch
5 times, most recently
from
a6f1227 to
a28582a
Compare
… failure The `cut -c` approach is *per line*, not *per file* as I had thought. So it does not work... Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
This is a crude, and incomplete, way to diagnose getenv() issues where the return value is not used transiently. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
The return value of getenv() is not guaranteed to remain valid across multiple calls (nor across calls to setenv()). Since this function caches the result for the length of the program, we must make a copy to ensure that it is still valid when we need it. Reported-by: Yngve N. Pettersen <yngve@vivaldi.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
We save the result of $GIT_INDEX_FILE so that we can restore it after setting it to a new value and running add--interactive. However, the pointer returned by getenv() is not guaranteed to be valid after calling setenv(). This _usually_ works fine, but can fail if libc needs to reallocate the environment block during the setenv(). Let's just duplicate the string, so we know that it remains valid. In the long run it may be more robust to teach interactive_add() to take a set of environment variables to pass along to run-command when it execs add--interactive. And then we would not have to do this save/restore dance at all. But this is an easy fix in the meantime. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
cmd_config() points our source filename pointer at the return value of getenv(), but that value may be invalidated by further calls to environment functions. Let's copy it to make sure it remains valid. We don't need to bother freeing it, as it remains part of the whole-process global state until we exit. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
We pass the result of getenv("GIT_DIR") to init_db() and assume that the
string remains valid. But that's not guaranteed across calls to setenv()
or even getenv(), although it often works in practice. Let's make a copy
of the string so that we follow the rules.
Note that we need to mark it with UNLEAK(), since the value persists
until the end of program (but we have no opportunity to free it).
This patch also handles $GIT_WORK_TREE the same way. It actually doesn't
have as long a lifetime and is probably fine, but it's simpler to just
treat the two side-by-side variables the same.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If $GITHEAD_1234abcd is set in the environment, we use its value as a "better branch name" in generating conflict markers. However, we pick these better names early in the process, and the return value from getenv() is not guaranteed to stay valid. Let's make a copy of the returned string. And to make memory management easier, let's just always return an allocated string from better_branch_name(), so we know that it must always be freed. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
The value returned by getenv() is not guaranteed to remain valid across other environment function calls. But in between our call and using the value, we run fill_textconv(), which may do quite a bit of work, including spawning sub-processes. We can make this safer by calling getenv() right before we actually look at its value. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
There are a couple of
getenv()issues where the return value is not used transiently. This is not correct, and causes problems with our new environment handling that retains only 30 getenv() calls' return value (and then starts invalidating the 31st-latest one).