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Re: [msysGit] [PATCH 1/2] MSVC: Do not close stdout to prevent a crash

From
Johannes Sixt <j6t@kdbg.org>
Date
Nov 19, 2011, 20:11 UTC
Message-ID
<4EC80D84.2010202@kdbg.org>
In-Reply-To
<1321710345-2299-1-git-send-email-vfr@lyx.org>
Am 19.11.2011 14:45, schrieb Vincent van Ravesteijn:
Show 5 quoted lines
> When compiled with MSVC, git crashes on Windows when calling
> fstat(stdout) when stdout is closed. fstat is being called at the end of
> run_builtin and this will thus be a problem for builtin command that close
> stdout. This happens for 'format-patch' which closes stdout after a call to
> freopen which directs stdout to the format patch file.

This crash happens because of the some drainbramage in the MS's newer C runtime: Its functions never return EINVAL (like fstat should in this case), but it is assumed that cases where EINVAL should be returned are programming errors, and the application is redirected, via an "invalid agument handler" to abort() instead. (It is advertized as a security feature.)

> To prevent the crash and to prevent git from writing cruft into the patch
> file, we do not close stdout, but redirect it to "nul" instead.

A more robust solution is to add invalidcontinue.obj to the linker command line. This installs an invalid argument handler that does not abort, and restores a sane behavior.

-- Hannes
Previous: Vincent van RavesteijnNext: Vincent van Ravesteijn
Message 11 of 14 in “MSVC: Do not close stdout to prevent a crash”
  1. 1/2 MSVC: Do not close stdout to prevent a crashVincent van Ravesteijn, Nov 19, 2011
  2. 2/2 MSVC: Use _putenv instead of putenv to prevent a crashVincent van Ravesteijn, Nov 19, 2011
  3. Andreas SchwabNov 19, 2011
  4. Junio C HamanoNov 19, 2011
  5. Andreas SchwabNov 19, 2011
  6. Junio C HamanoNov 20, 2011
  7. Andreas SchwabNov 20, 2011
  8. Johannes SixtNov 20, 2011
  9. Junio C HamanoNov 20, 2011
  10. Vincent van RavesteijnNov 19, 2011
  11. Johannes SixtNov 19, 2011
  12. Vincent van RavesteijnNov 22, 2011
  13. Johannes SixtNov 22, 2011
  14. Vincent van RavesteijnNov 22, 2011

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