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Re: Using clean/smudge filters with difftool

From
Junio C Hamano <gitster@pobox.com>
Date
Jun 18, 2015, 20:00 UTC
Message-ID
<xmqqsi9oeqhn.fsf@gitster.dls.corp.google.com>
In-Reply-To
<20150618160133.GO18226@serenity.lan>
John Keeping <john@keeping.me.uk> writes:
Show 9 quoted lines
> I think this is a difference between git-diff's internal and external
> diff modes which is working correctly, although possibly not desirably
> in this case.  The internal diff always uses clean files (so it runs the
> working tree file through the "clean" filter before applying the diff
> algorithm) but the external diff uses the working tree file so it
> applies the "smudge" filter to any blobs that it needs to checkout.
>
> Commit 4e218f5 (Smudge the files fed to external diff and textconv,
> 2009-03-21) was the source of this behaviour.

The fundamental design to use smudged version when interacting with external programs actually predates that particular commit, I think.

The caller of the function that was updated by that commit, i.e. prepare_temp_file(), reuses what is checked out to the working tree when we can (i.e. it hasn't been modified from what we think is checked out) and when it is beneficial to do so (i.e. on a system with FAST_WORKING_DIRECTORY defined), which means the temporary file given by the prepare_temp_file() that is used by the external tools (both --ext-diff program and textconv filter) are designed to be fed and work on the smudged version of the file. 4e218f5 did not change that fundamental design; it just made things more consistent between the case where we do create a new temporary file out of blob and we allow an unmodified checked out file to be reused.

Previous: John KeepingNext: John Keeping
Message 11 of 18 in “Using clean/smudge filters with difftool”
  1. Florian AspartJun 16, 2015
  2. Michael J GruberJun 18, 2015
  3. Florian AspartJun 18, 2015
  4. John KeepingJun 18, 2015
  5. Florian AspartJun 18, 2015
  6. John KeepingJun 18, 2015
  7. Florian AspartJun 18, 2015
  8. John KeepingJun 18, 2015
  9. Florian AspartJun 18, 2015
  10. John KeepingJun 18, 2015
  11. Junio C HamanoJun 18, 2015
  12. John KeepingJun 18, 2015
  13. Junio C HamanoJun 18, 2015
  14. Michael J GruberJun 19, 2015
  15. John KeepingJun 19, 2015
  16. Florian AspartJun 19, 2015
  17. Junio C HamanoJun 19, 2015
  18. Michael J GruberJun 21, 2015

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