Commit Graph

192 Commits

Author SHA1 Message Date
Alex Riesen
9fa03c177f Fix potentially dangerous uses of mkpath and git_path
Replace them with mksnpath/git_snpath and a local buffer
for the resulting string.

Signed-off-by: Alex Riesen <raa.lkml@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-10-26 22:10:28 -07:00
Jeff King
969c877506 git apply --directory broken for new files
We carefully verify that the input to git-apply is sane,
including cross-checking that the filenames we see in "+++"
headers match what was provided on the command line of "diff
--git". When --directory is used, however, we ended up
comparing the unadorned name to one with the prepended root,
causing us to complain about a mismatch.

We simply need to prepend the root directory, if any, when
pulling the name out of the git header.

Signed-off-by: Jeff King <peff@peff.net>
Acked-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2008-10-12 11:09:41 -07:00
Imre Deak
b8ebe08b9a builtin-apply: fix typo leading to stack corruption
This typo led to stack corruption for lines with whitespace fixes
and length > 1024.

Signed-off-by: Imre Deak <imre.deak@gmail.com>
Looks-good-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2008-10-09 09:21:50 -07:00
Dmitry Potapov
d09e2cd551 do not segfault if make_cache_entry failed
Signed-off-by: Dmitry Potapov <dpotapov@gmail.com>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2008-10-06 00:49:57 -07:00
Alex Riesen
175a494823 Use remove_path from dir.c instead of own implementation
Besides, it fixes a memleak (builtin-rm.c) and accidental change of
the input const argument (builtin-merge-recursive.c).

Signed-off-by: Alex Riesen <raa.lkml@gmail.com>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2008-09-29 08:37:07 -07:00
Junio C Hamano
36f44a0680 Merge branch 'ho/dashless' into maint
* ho/dashless:
  tests: use "git xyzzy" form (t7200 - t9001)
  tests: use "git xyzzy" form (t7000 - t7199)
  tests: use "git xyzzy" form (t3600 - t6999)
  tests: use "git xyzzy" form (t0000 - t3599)
  'git foo' program identifies itself without dash in die() messages
  Start conforming code to "git subcmd" style
2008-09-03 14:51:56 -07:00
Junio C Hamano
7e44c93558 'git foo' program identifies itself without dash in die() messages
This is a mechanical conversion of all '*.c' files with:

	s/((?:die|error|warning)\("git)-(\S+:)/$1 $2/;

The result was manually inspected and no false positive was found.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-08-31 09:39:19 -07:00
Heikki Orsila
34baebcee1 Start conforming code to "git subcmd" style
User notifications are presented as 'git cmd', and code comments
are presented as '"cmd"' or 'git's cmd', rather than 'git-cmd'.

Signed-off-by: Heikki Orsila <heikki.orsila@iki.fi>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-08-30 13:50:48 -07:00
Junio C Hamano
ed0f47a8c4 git-apply: Loosen "match_beginning" logic
Even after a handfle attempts, match_beginning logic still has corner
cases:

    1bf1a85 (apply: treat EOF as proper context., 2006-05-23)
    65aadb9 (apply: force matching at the beginning., 2006-05-24)
    4be6096 (apply --unidiff-zero: loosen sanity checks ..., 2006-09-17)
    ee5a317 (Fix "git apply" to correctly enforce "match ..., 2008-04-06)

This is a tricky piece of code.

We still incorrectly enforce "match_beginning" for -U0 matches.
I noticed this while trying out an example sequence from Clemens Buchacher:

    $ echo a >victim
    $ git add victim
    $ echo b >>victim
    $ git diff -U0 >patch
    $ cat patch
    diff --git i/victim w/victim
    index 7898192..422c2b7 100644
    --- i/victim
    +++ w/victim
    @@ -1,0 +2 @@ a
    +b
    $ git apply --cached --unidiff-zero <patch
    $ git show :victim
    b
    a

The change inserts a new line before the second line, but we insist it to
be applied at the beginning.  As the result, the code refuses to apply it
at the original offset, and we end up adding the line at the beginning.

Updates to the test script are by Clemens Buchacher.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-08-30 13:23:02 -07:00
Johannes Schindelin
c455c87c5c Rename path_list to string_list
The name path_list was correct for the first usage of that data structure,
but it really is a general-purpose string list.

$ perl -i -pe 's/path-list/string-list/g' $(git grep -l path-list)
$ perl -i -pe 's/path_list/string_list/g' $(git grep -l path_list)
$ git mv path-list.h string-list.h
$ git mv path-list.c string-list.c
$ perl -i -pe 's/has_path/has_string/g' $(git grep -l has_path)
$ perl -i -pe 's/path/string/g' string-list.[ch]
$ git mv Documentation/technical/api-path-list.txt \
	Documentation/technical/api-string-list.txt
$ perl -i -pe 's/strdup_paths/strdup_strings/g' $(git grep -l strdup_paths)

... and then fix all users of string-list to access the member "string"
instead of "path".

Documentation/technical/api-string-list.txt needed some rewrapping, too.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-07-21 19:11:50 -07:00
Stephan Beyer
1b1dd23f2d Make usage strings dash-less
When you misuse a git command, you are shown the usage string.
But this is currently shown in the dashed form.  So if you just
copy what you see, it will not work, when the dashed form
is no longer supported.

This patch makes git commands show the dash-less version.

For shell scripts that do not specify OPTIONS_SPEC, git-sh-setup.sh
generates a dash-less usage string now.

Signed-off-by: Stephan Beyer <s-beyer@gmx.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-07-13 14:12:48 -07:00
Junio C Hamano
a9a3e82e6d apply: fix copy/rename breakage
7ebd52a (Merge branch 'dz/apply-again', 2008-07-01) taught "git-apply" to
grok a (non-git) patch that is a concatenation of separate patches that
touch the same file number of times, by recording the postimage of patch
application of previous round and using it as the preimage for later
rounds.

This "incremental" mode of patch application fundamentally contradicts
with the way git rename/copy patches are designed.  When a git patch talks
about a file A getting modified, and a new file B created out of A, like
this:

	diff --git a/A b/A
	--- a/A
	+++ b/A
	... change text here ...
	diff --git a/A b/B
	copy from A
	copy to B
	--- a/A
	+++ b/B
	... change text here ...

the second change to produce B does not depend on what is done to A with
the first change in any way.  This is explicitly done so for reviewability
of individual patches.

With this commit, we do not look at 'fn_table' that records the postimage
of previous round when applying a patch to produce a new file out of an
existing file.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-07-09 20:31:44 -07:00
Junio C Hamano
e9a9d6edee Merge branch 'js/apply-root'
* js/apply-root:
  git-apply --directory: make --root more similar to GNU diff
  apply --root: thinkofix.
  Teach "git apply" to prepend a prefix with "--root=<root>"
2008-07-09 16:58:21 -07:00
Junio C Hamano
f556388747 git-apply --directory: make --root more similar to GNU diff
Applying a patch in the directory that is different from what the patch
records is done with --directory option in GNU diff.  The --root option we
introduced previously does the same, and we can call it the same way to
give users more familiar feel.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-07-06 19:33:08 -07:00
Thomas Rast
6cf91492d9 Fix apply --recount handling of no-EOL line
If a patch modifies the last line of a file that previously had no
terminating '\n', it looks like

    -old text
    \ No newline at end of file
    +new text

Hence, a '\' line does not signal the end of the hunk.  This modifies
'git apply --recount' to take this into account.

Signed-off-by: Thomas Rast <trast@student.ethz.ch>
Acked-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-07-05 00:37:44 -07:00
Junio C Hamano
8ee4a6c2ec apply --root: thinkofix.
The end of a string is string[length-1], not string[length+1].
I pointed it out during the review, but I forgot about it when applying the
patch.  This should fix it.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-07-02 15:28:22 -07:00
Johannes Schindelin
c4730f35cc Teach "git apply" to prepend a prefix with "--root=<root>"
With "git apply --root=<root>", all file names in the patch are prepended
with <root>.  If a "-p" value was given, the paths are stripped _before_
prepending <root>.

Wished for by HPA.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-07-01 18:04:28 -07:00
Junio C Hamano
27158e463a Merge branch 'js/apply-recount'
* js/apply-recount:
  Allow git-apply to recount the lines in a hunk (AKA recountdiff)
2008-07-01 16:22:39 -07:00
Junio C Hamano
d4b76e15ea Merge branch 'jc/checkdiff'
* jc/checkdiff:
  Fix t4017-diff-retval for white-space from wc
  Update sample pre-commit hook to use "diff --check"
  diff --check: detect leftover conflict markers
  Teach "diff --check" about new blank lines at end
  checkdiff: pass diff_options to the callback
  check_and_emit_line(): rename and refactor
  diff --check: explain why we do not care whether old side is binary
2008-07-01 16:22:35 -07:00
Johannes Schindelin
c14b9d1e33 Allow git-apply to recount the lines in a hunk (AKA recountdiff)
Sometimes, the easiest way to fix up a patch is to edit it directly, even
adding or deleting lines.  Now, many people are not as divine as certain
benevolent dictators as to update the hunk headers correctly at the first
try.

So teach the tool to do it for us.

[jc: with tests]

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-06-28 01:19:42 -07:00
Don Zickus
7a07841c0b git-apply: handle a patch that touches the same path more than once better
When working with a lot of people who backport patches all day long, every
once in a while I get a patch that modifies the same file more than once
inside the same patch.  git-apply either fails if the second change relies
on the first change or silently drops the first change if the second change
is independent.

The silent part is the scary scenario for us.  Also this behaviour is
different from the patch-utils.

I have modified git-apply to create a table of the filenames of files it
modifies such that if a later patch chunk modifies a file in the table it
will buffer the previously changed file instead of reading the original file
from disk.

Logic has been put in to handle creations/deletions/renames/copies.  All the
relevant tests of git-apply succeed.

A new test has been added to cover the cases I addressed.

The fix is relatively straight-forward.

Signed-off-by: Don Zickus <dzickus@redhat.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-06-27 17:01:02 -07:00
Junio C Hamano
8f8841e9c8 check_and_emit_line(): rename and refactor
The function name was too bland and not explicit enough as to what it is
checking.  Split it into two, and call the one that checks if there is a
whitespace breakage "ws_check()", and call the other one that checks and
emits the line after color coding "ws_check_emit()".

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-06-26 18:13:50 -07:00
Junio C Hamano
9bd81e4249 Merge branch 'js/config-cb'
* js/config-cb:
  Provide git_config with a callback-data parameter

Conflicts:

	builtin-add.c
	builtin-cat-file.c
2008-05-25 14:25:02 -07:00
Junio C Hamano
032bea55a3 builtin-apply: do not declare patch is creation when we do not know it
When we see no context nor deleted line in the patch, we used to declare
that the patch creates a new file.  But some people create an empty file
and then apply a patch to it.  Similarly, a patch that delete everything
is not a deletion patch either.

This commit corrects these two issues.  Together with the previous commit,
it allows a diff between an empty file and a line-ful file to be treated
as both creation patch and "add stuff to an existing empty file",
depending on the context.  A new test t4126 demonstrates the fix.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-05-17 02:57:33 -07:00
Junio C Hamano
5c47f4c6e7 builtin-apply: accept patch to an empty file
A patch from a foreign SCM (or plain "diff" output) often have both
preimage and postimage filename on ---/+++ lines even for a patch that
creates a new file.  However, when there is a filename for preimage, we
used to insist the file to exist (either in the work tree and/or in the
index).  When we cannot be sure by parsing the patch that it is not a
creation patch, we shouldn't complain when if there is no such a file.
This commit fixes the logic.

Refactor the code that validates the preimage file into a separate
function while we are at it, as it is getting rather big.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-05-17 01:51:31 -07:00
Junio C Hamano
88f6dbaf99 builtin-apply: typofix
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-05-17 01:46:47 -07:00
Johannes Schindelin
ef90d6d420 Provide git_config with a callback-data parameter
git_config() only had a function parameter, but no callback data
parameter.  This assumes that all callback functions only modify
global variables.

With this patch, every callback gets a void * parameter, and it is hoped
that this will help the libification effort.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-05-14 12:34:44 -07:00
Linus Torvalds
c40641b77b Optimize symlink/directory detection
This is the base for making symlink detection in the middle fo a pathname
saner and (much) more efficient.

Under various loads, we want to verify that the full path leading up to a
filename is a real directory tree, and that when we successfully do an
'lstat()' on a filename, we don't get a false positive due to a symlink in
the middle of the path that git should have seen as a symlink, not as a
normal path component.

The 'has_symlink_leading_path()' function already did this, and cached
a single level of symlink information, but didn't cache the _lack_ of a
symlink, so the normal behaviour was actually the wrong way around, and we
ended up doing an 'lstat()' on each path component to check that it was a
real directory.

This caches the last detected full directory and symlink entries, and
speeds up especially deep directory structures a lot by avoiding to
lstat() all the directories leading up to each entry in the index.

[ This can - and should - probably be extended upon so that we eventually
  never do a bare 'lstat()' on any path entries at *all* when checking the
  index, but always check the full path carefully. Right now we do not
  generally check the whole path for all our normal quick index
  revalidation.

  We should also make sure that we're careful about all the invalidation,
  ie when we remove a link and replace it by a directory we should
  invalidate the symlink cache if it matches (and vice versa for the
  directory cache).

  But regardless, the basic function needs to be sane to do that. The old
  'has_symlink_leading_path()' was not capable enough - or indeed the code
  readable enough - to really do that sanely. So I'm pushing this as not
  just an optimization, but as a base for further work. ]

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-05-10 18:16:31 -07:00
Junio C Hamano
a17b1d2f0b Merge branch 'maint'
* maint:
  git-bisect: make "start", "good" and "skip" succeed or fail atomically
  git-am: cope better with an empty Subject: line
  Ignore leading empty lines while summarizing merges
  bisect: squelch "fatal: ref HEAD not a symref" misleading message
  builtin-apply: Show a more descriptive error on failure when opening a patch
  Clarify documentation of git-cvsserver, particularly in relation to git-shell
2008-04-16 00:45:52 -07:00
Junio C Hamano
464509f790 Merge branch 'maint-1.5.4' into maint
* maint-1.5.4:
  git-bisect: make "start", "good" and "skip" succeed or fail atomically
  git-am: cope better with an empty Subject: line
  Ignore leading empty lines while summarizing merges
  bisect: squelch "fatal: ref HEAD not a symref" misleading message
  builtin-apply: Show a more descriptive error on failure when opening a patch
  Clarify documentation of git-cvsserver, particularly in relation to git-shell
2008-04-16 00:37:33 -07:00
Alberto Bertogli
1da16439be builtin-apply: Show a more descriptive error on failure when opening a patch
When a patch can't be opened (it doesn't exist, there are permission
problems, etc.) we get the usage text, which is not a proper indication of
failure.

Signed-off-by: Alberto Bertogli <albertito@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-04-15 22:42:08 -07:00
Stephan Beyer
8e4c6aa1ac builtin-apply.c: use git_config_string() to get apply_default_whitespace
Signed-off-by: Stephan Beyer <s-beyer@gmx.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-04-14 22:37:47 -07:00
Junio C Hamano
a1c0dca43a Merge branch 'jc/maint-apply-match-beginning'
* jc/maint-apply-match-beginning:
  Fix "git apply" to correctly enforce "match at the beginning"
2008-04-06 20:04:29 -07:00
Junio C Hamano
ee5a317e01 Fix "git apply" to correctly enforce "match at the beginning"
An earlier commit 4be6096 (apply --unidiff-zero: loosen sanity checks for
--unidiff=0 patches, 2006-09-17) made match_beginning and match_end
computed incorrectly.  If a hunk inserts at the beginning, old position
recorded at the hunk is line 0, and if a hunk changes at the beginning, it
is line 1.  The new test added to t4104 exposes that the old code did not
insist on matching at the beginning for a patch to add a line to an empty
file.

An even older 65aadb9 (apply: force matching at the beginning.,
2006-05-24) was equally wrong in that it tried to take hints from the
number of leading context lines, to decide if the hunk must match at the
beginning, but we can just look at the line number in the hunk to decide.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-04-06 19:21:45 -07:00
SZEDER Gábor
af05d67939 Always set *nongit_ok in setup_git_directory_gently()
setup_git_directory_gently() only modified the value of its *nongit_ok
argument if we were not in a git repository.  Now it will always set it
to 0 when we are inside a repository.

Also remove now unnecessary initializations in the callers of this
function.

Signed-off-by: SZEDER Gábor <szeder@ira.uka.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-03-26 15:41:35 -07:00
Junio C Hamano
e38f892d18 Merge branch 'jc/apply-whitespace'
* jc/apply-whitespace:
  ws_fix_copy(): move the whitespace fixing function to ws.c
  apply: do not barf on patch with too large an offset
  core.whitespace: cr-at-eol
  git-apply --whitespace=fix: fix whitespace fuzz introduced by previous run
  builtin-apply.c: pass ws_rule down to match_fragment()
  builtin-apply.c: move copy_wsfix() function a bit higher.
  builtin-apply.c: do not feed copy_wsfix() leading '+'
  builtin-apply.c: simplify calling site to apply_line()
  builtin-apply.c: clean-up apply_one_fragment()
  builtin-apply.c: mark common context lines in lineinfo structure.
  builtin-apply.c: optimize match_beginning/end processing a bit.
  builtin-apply.c: make it more line oriented
  builtin-apply.c: push match-beginning/end logic down
  builtin-apply.c: restructure "offset" matching
  builtin-apply.c: refactor small part that matches context
2008-02-24 17:23:17 -08:00
Junio C Hamano
fe3403c320 ws_fix_copy(): move the whitespace fixing function to ws.c
This is used by git-apply but we can use it elsewhere by slightly
generalizing it.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-02-23 16:59:16 -08:00
Junio C Hamano
2ac4b4b222 Merge branch 'sp/safecrlf'
* sp/safecrlf:
  safecrlf: Add mechanism to warn about irreversible crlf conversions
2008-02-16 17:59:20 -08:00
Junio C Hamano
e0197c9aae Merge branch 'lt/in-core-index'
* lt/in-core-index:
  lazy index hashing
  Create pathname-based hash-table lookup into index
  read-cache.c: introduce is_racy_timestamp() helper
  read-cache.c: fix a couple more CE_REMOVE conversion
  Also use unpack_trees() in do_diff_cache()
  Make run_diff_index() use unpack_trees(), not read_tree()
  Avoid running lstat(2) on the same cache entry.
  index: be careful when handling long names
  Make on-disk index representation separate from in-core one
2008-02-11 16:46:20 -08:00
Junio C Hamano
52f3c81a9d apply: do not barf on patch with too large an offset
Previously a patch that records too large a line number caused the
offset matching code in git-apply to overstep its internal buffer.

Noticed by Johannes Schindelin.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-02-11 15:48:10 -08:00
Junio C Hamano
a0ed3e6ade builtin-apply.c: guard config parser from value=NULL
apply.whitespace configuration expects a string value.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-02-11 13:11:36 -08:00
Steffen Prohaska
21e5ad50fc safecrlf: Add mechanism to warn about irreversible crlf conversions
CRLF conversion bears a slight chance of corrupting data.
autocrlf=true will convert CRLF to LF during commit and LF to
CRLF during checkout.  A file that contains a mixture of LF and
CRLF before the commit cannot be recreated by git.  For text
files this is the right thing to do: it corrects line endings
such that we have only LF line endings in the repository.
But for binary files that are accidentally classified as text the
conversion can corrupt data.

If you recognize such corruption early you can easily fix it by
setting the conversion type explicitly in .gitattributes.  Right
after committing you still have the original file in your work
tree and this file is not yet corrupted.  You can explicitly tell
git that this file is binary and git will handle the file
appropriately.

Unfortunately, the desired effect of cleaning up text files with
mixed line endings and the undesired effect of corrupting binary
files cannot be distinguished.  In both cases CRLFs are removed
in an irreversible way.  For text files this is the right thing
to do because CRLFs are line endings, while for binary files
converting CRLFs corrupts data.

This patch adds a mechanism that can either warn the user about
an irreversible conversion or can even refuse to convert.  The
mechanism is controlled by the variable core.safecrlf, with the
following values:

 - false: disable safecrlf mechanism
 - warn: warn about irreversible conversions
 - true: refuse irreversible conversions

The default is to warn.  Users are only affected by this default
if core.autocrlf is set.  But the current default of git is to
leave core.autocrlf unset, so users will not see warnings unless
they deliberately chose to activate the autocrlf mechanism.

The safecrlf mechanism's details depend on the git command.  The
general principles when safecrlf is active (not false) are:

 - we warn/error out if files in the work tree can modified in an
   irreversible way without giving the user a chance to backup the
   original file.

 - for read-only operations that do not modify files in the work tree
   we do not not print annoying warnings.

There are exceptions.  Even though...

 - "git add" itself does not touch the files in the work tree, the
   next checkout would, so the safety triggers;

 - "git apply" to update a text file with a patch does touch the files
   in the work tree, but the operation is about text files and CRLF
   conversion is about fixing the line ending inconsistencies, so the
   safety does not trigger;

 - "git diff" itself does not touch the files in the work tree, it is
   often run to inspect the changes you intend to next "git add".  To
   catch potential problems early, safety triggers.

The concept of a safety check was originally proposed in a similar
way by Linus Torvalds.  Thanks to Dimitry Potapov for insisting
on getting the naked LF/autocrlf=true case right.

Signed-off-by: Steffen Prohaska <prohaska@zib.de>
2008-02-06 13:07:28 -08:00
Junio C Hamano
b2979ff599 core.whitespace: cr-at-eol
This new error mode allows a line to have a carriage return at the
end of the line when checking and fixing trailing whitespace errors.

Some people like to keep CRLF line ending recorded in the repository,
and still want to take advantage of the automated trailing whitespace
stripping.  We still show ^M in the diff output piped to "less" to
remind them that they do have the CR at the end, but these carriage
return characters at the end are no longer flagged as errors.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-02-05 00:38:41 -08:00
Junio C Hamano
c1beba5b47 git-apply --whitespace=fix: fix whitespace fuzz introduced by previous run
When you have more than one patch series, an earlier one of which
tries to introduce whitespace breakages and a later one of which
has such a new line in its context, "git-apply --whitespace=fix"
will apply and fix the whitespace breakages in the earlier one,
making the resulting file not to match the context of the later
patch.

A short demonstration is in the new test, t4125.

For example, suppose the first patch is:

    diff a/hello.txt b/hello.txt
    --- a/hello.txt
    +++ b/hello.txt
    @@ -20,3 +20,3 @@
     Hello world.$
    -How Are you$
    -Today?$
    +How are you $
    +today? $

to fix broken case in the string, but it introduces unwanted
trailing whitespaces to the result (pretend you are looking at
"cat -e" output of the patch --- '$' signs are not in the patch
but are shown to make the EOL stand out).  And the second patch
is to change the wording of the greeting further:

    diff a/hello.txt b/hello.txt
    --- a/hello.txt
    +++ b/hello.txt
    @@ -18,5 +18,5 @@
     Greetings $

    -Hello world.$
    +Hello, everybody. $
     How are you $
    -today? $
    +these days? $

If you apply the first one with --whitespace=fix, you will get
this as the result:

    Hello world.$
    How are you$
    today?$

and this does not match the preimage of the second patch, which
demands extra whitespace after "How are you" and "today?".

This series is about teaching "git apply --whitespace=fix" to
cope with this situation better.  If the patch does not apply,
it rewrites the second patch like this and retries:

    diff a/hello.txt b/hello.txt
    --- a/hello.txt
    +++ b/hello.txt
    @@ -18,5 +18,5 @@
     Greetings$

    -Hello world.$
    +Hello, everybody.$
     How are you$
    -today?$
    +these days?$

This is done by rewriting the preimage lines in the hunk
(i.e. the lines that begin with ' ' or '-'), using the same
whitespace fixing rules as it is using to apply the patches, so
that it can notice what it did to the previous ones in the
series.

A careful reader may notice that the first patch in the example
did not touch the "Greetings" line, so the trailing whitespace
that is in the original preimage of the second patch is not from
the series.  Is rewriting this context line a problem?

If you think about it, you will realize that the reason for the
difference is because the submitter's tree was based on an
earlier version of the file that had whitespaces wrong on that
"Greetings" line, and the change that introduced the "Greetings"
line was added independently of this two-patch series to our
tree already with an earlier "git apply --whitespace=fix".

So it may appear this logic is rewriting too much, it is not
so.  It is just rewriting what we would have rewritten in the
past.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-02-05 00:38:41 -08:00
Junio C Hamano
c607aaa2f0 builtin-apply.c: pass ws_rule down to match_fragment()
This is necessary to allow match_fragment() to attempt a match
with a preimage that is based on a version before whitespace
errors were fixed.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-02-05 00:38:41 -08:00
Junio C Hamano
ee810b7159 builtin-apply.c: move copy_wsfix() function a bit higher.
I'll be calling this from match_fragment() in later rounds.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-02-05 00:38:41 -08:00
Junio C Hamano
42ab241cfa builtin-apply.c: do not feed copy_wsfix() leading '+'
The "patch" parameter used to include leading '+' of an added
line in the patch, and the array was treated as 1-based.  Make
it accept the contents of the line alone and simplify the code.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-02-05 00:38:41 -08:00
Junio C Hamano
8441a9a842 builtin-apply.c: simplify calling site to apply_line()
The function apply_line() changed its behaviour depending on the
ws_error_action, whitespace_error and if the input was a context.
Make its caller responsible for such checking so that we can convert
the function to copy the contents of line while fixing whitespace
breakage more easily.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-02-05 00:38:41 -08:00
Junio C Hamano
61e08ccacb builtin-apply.c: clean-up apply_one_fragment()
We had two pointer variables pointing to the same buffer and an
integer variable used to index into its tail part that was
active (old, oldlines and oldsize for the preimage, and their
'new' counterparts for the postimage).

To help readability, use 'oldlines' as the allocated pointer,
and use 'old' as the pointer to the tail that advances while the
code builds up the contents in the buffer.  The size 'oldsize'
can be computed as (old-oldines).

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-02-05 00:38:41 -08:00
Junio C Hamano
c330fdd42d builtin-apply.c: mark common context lines in lineinfo structure.
This updates the way preimage and postimage in a patch hunk is
parsed and prepared for applying.  By looking at image->line[n].flag,
the code can tell if it is a common context line that is the
same between the preimage and the postimage.

This matters when we actually start applying a patch with
contexts that have whitespace breakages that have already been
fixed in the target file.
2008-02-05 00:38:41 -08:00