On Wed, 14 Apr 2010, Stefan Sperling wrote: > Yes. Just use whatever comes from the patch, including context lines. > This is consistent with the current behaviour. I think we should avoid > special cases where this rule is currently not true anymore. > (I'm not sure how UNIX patch behaves wrt context lines, actually. > Might be worth checking.)
If applying a patch ever causes changes to lines that are marked in the patch as context lines (not as lines to be removed or added), then I expect people to be unhappy. The context lines in the patch file are known or suspected to be damaged (or else the user would not have asked to ignore whitespace changes), so copying the context lines from the patch is not wanted. The GNU patch implementation that I just tried does the right thing here: when passed the "--ignore-whitespace" option, it ignores whitespace changes in context lines and lines marked as being removed, and it copies context lines from the input file, not from the patch. I don't buy the argument that it's necessary, for consistency with current svn behaviour, to copy context lines from the patch to the output file. Current behaviour does not include any kind of "ignore whitespace" option, so the context lines in the input file are guaranteed not to differ from the context lines in the patch, so an outside observer (without knowledge of the internals of the implementation) cannot tell whether the current implementation copies context lines from the patch or from the input file. Changing the implementation to copy context lines from the input file would therefore not be an incompatible change. --apb (Alan Barrett)
