Mercurial > hg
view tests/test-diff-ignore-whitespace.t @ 23702:c48924787eaa
filectx.parents: enforce changeid of parent to be in own changectx ancestors
Because of the way filenodes are computed, you can have multiple changesets
"introducing" the same file revision. For example, in the changeset graph
below, changeset 2 and 3 both change a file -to- and -from- the same content.
o 3: content = new
|
| o 2: content = new
|/
o 1: content = old
In such cases, the file revision is create once, when 2 is added, and just reused
for 3. So the file change in '3' (from "old" to "new)" has no linkrev pointing
to it). We'll call this situation "linkrev-shadowing". As the linkrev is used for
optimization purposes when walking a file history, the linkrev-shadowing
results in an unexpected jump to another branch during such a walk.. This leads to
multiple bugs with log, annotate and rename detection.
One element to fix such bugs is to ensure that walking the file history sticks on
the same topology as the changeset's history. For this purpose, we extend the
logic in 'basefilectx.parents' so that it always defines the proper changeset
to associate the parent file revision with. This "proper" changeset has to be an
ancestor of the changeset associated with the child file revision.
This logic is performed in the '_adjustlinkrev' function. This function is
given the starting changeset and all the information regarding the parent file
revision. If the linkrev for the file revision is an ancestor of the starting
changeset, the linkrev is valid and will be used. If it is not, we detected a
topological jump caused by linkrev shadowing, we are going to walk the
ancestors of the starting changeset until we find one setting the file to the
revision we are trying to create.
The performance impact appears acceptable:
- We are walking the changelog once for each filelog traversal (as there should
be no overlap between searches),
- changelog traversal itself is fairly cheap, compared to what is likely going
to be perform on the result on the filelog traversal,
- We only touch the manifest for ancestors touching the file, And such
changesets are likely to be the one introducing the file. (except in
pathological cases involving merge),
- We use manifest diff instead of full manifest unpacking to check manifest
content, so it does not involve applying multiple diffs in most case.
- linkrev shadowing is not the common case.
Tests for fixed issues in log, annotate and rename detection have been
added.
But this changeset does not solve all problems. It fixes -ancestry-
computation, but if the linkrev-shadowed changesets is the starting one, we'll
still get things wrong. We'll have to fix the bootstrapping of such operations
in a later changeset. Also, the usage of `hg log FILE` without --follow still
has issues with linkrev pointing to hidden changesets, because it relies on the
`filelog` revset which implement its own traversal logic that is still to be
fixed.
Thanks goes to:
- Matt Mackall: for nudging me in the right direction
- Julien Cristau and RĂ©mi Cardona: for keep telling me linkrev bug were an
evolution show stopper for 3 years.
- Durham Goode: for finding a new linkrev issue every few weeks
- Mads Kiilerich: for that last rename bug who raise this topic over my
anoyance limit.
author | Pierre-Yves David <pierre-yves.david@fb.com> |
---|---|
date | Tue, 23 Dec 2014 15:30:38 -0800 |
parents | 405b6bd015df |
children | da07367d683b |
line wrap: on
line source
GNU diff is the reference for all of these results. Prepare tests: $ echo '[alias]' >> $HGRCPATH $ echo 'ndiff = diff --nodates' >> $HGRCPATH $ hg init $ printf 'hello world\ngoodbye world\n' >foo $ hg ci -Amfoo -ufoo adding foo Test added blank lines: $ printf '\nhello world\n\ngoodbye world\n\n' >foo >>> two diffs showing three added lines <<< $ hg ndiff diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,5 @@ + hello world + goodbye world + $ hg ndiff -b diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,5 @@ + hello world + goodbye world + >>> no diffs <<< $ hg ndiff -B $ hg ndiff -Bb Test added horizontal space first on a line(): $ printf '\t hello world\ngoodbye world\n' >foo >>> four diffs showing added space first on the first line <<< $ hg ndiff diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,2 @@ -hello world + hello world goodbye world $ hg ndiff -b diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,2 @@ -hello world + hello world goodbye world $ hg ndiff -B diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,2 @@ -hello world + hello world goodbye world $ hg ndiff -Bb diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,2 @@ -hello world + hello world goodbye world Test added horizontal space last on a line: $ printf 'hello world\t \ngoodbye world\n' >foo >>> two diffs showing space appended to the first line <<< $ hg ndiff diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,2 @@ -hello world +hello world goodbye world $ hg ndiff -B diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,2 @@ -hello world +hello world goodbye world >>> no diffs <<< $ hg ndiff -b $ hg ndiff -Bb Test added horizontal space in the middle of a word: $ printf 'hello world\ngood bye world\n' >foo >>> four diffs showing space inserted into "goodbye" <<< $ hg ndiff diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,2 @@ hello world -goodbye world +good bye world $ hg ndiff -B diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,2 @@ hello world -goodbye world +good bye world $ hg ndiff -b diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,2 @@ hello world -goodbye world +good bye world $ hg ndiff -Bb diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,2 @@ hello world -goodbye world +good bye world Test increased horizontal whitespace amount: $ printf 'hello world\ngoodbye\t\t \tworld\n' >foo >>> two diffs showing changed whitespace amount in the last line <<< $ hg ndiff diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,2 @@ hello world -goodbye world +goodbye world $ hg ndiff -B diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,2 @@ hello world -goodbye world +goodbye world >>> no diffs <<< $ hg ndiff -b $ hg ndiff -Bb Test added blank line with horizontal whitespace: $ printf 'hello world\n \t\ngoodbye world\n' >foo >>> three diffs showing added blank line with horizontal space <<< $ hg ndiff diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,3 @@ hello world + goodbye world $ hg ndiff -B diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,3 @@ hello world + goodbye world $ hg ndiff -b diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,3 @@ hello world + goodbye world >>> no diffs <<< $ hg ndiff -Bb Test added blank line with other whitespace: $ printf 'hello world\n \t\ngoodbye world \n' >foo >>> three diffs showing added blank line with other space <<< $ hg ndiff diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,3 @@ -hello world -goodbye world +hello world + +goodbye world $ hg ndiff -B diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,3 @@ -hello world -goodbye world +hello world + +goodbye world $ hg ndiff -b diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,3 @@ hello world + goodbye world >>> no diffs <<< $ hg ndiff -Bb Test whitespace changes: $ printf 'helloworld\ngoodbye\tworld \n' >foo >>> four diffs showing changed whitespace <<< $ hg ndiff diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,2 @@ -hello world -goodbye world +helloworld +goodbye world $ hg ndiff -B diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,2 @@ -hello world -goodbye world +helloworld +goodbye world $ hg ndiff -b diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,2 @@ -hello world +helloworld goodbye world $ hg ndiff -Bb diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,2 @@ -hello world +helloworld goodbye world >>> no diffs <<< $ hg ndiff -w Test whitespace changes and blank lines: $ printf 'helloworld\n\n\n\ngoodbye\tworld \n' >foo >>> five diffs showing changed whitespace <<< $ hg ndiff diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,5 @@ -hello world -goodbye world +helloworld + + + +goodbye world $ hg ndiff -B diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,5 @@ -hello world -goodbye world +helloworld + + + +goodbye world $ hg ndiff -b diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,5 @@ -hello world +helloworld + + + goodbye world $ hg ndiff -Bb diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,5 @@ -hello world +helloworld + + + goodbye world $ hg ndiff -w diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,5 @@ hello world + + + goodbye world >>> no diffs <<< $ hg ndiff -wB Test \r (carriage return) as used in "DOS" line endings: $ printf 'hello world\r\n\r\ngoodbye\rworld\n' >foo $ hg ndiff diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,3 @@ -hello world -goodbye world +hello world\r (esc) +\r (esc) +goodbye\r (no-eol) (esc) world No completely blank lines to ignore: $ hg ndiff --ignore-blank-lines diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,3 @@ -hello world -goodbye world +hello world\r (esc) +\r (esc) +goodbye\r (no-eol) (esc) world Only new line noticed: $ hg ndiff --ignore-space-change diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,3 @@ hello world +\r (esc) goodbye world $ hg ndiff --ignore-all-space diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,3 @@ hello world +\r (esc) goodbye world New line not noticed when space change ignored: $ hg ndiff --ignore-blank-lines --ignore-all-space Do not ignore all newlines, only blank lines $ printf 'hello \nworld\ngoodbye world\n' > foo $ hg ndiff --ignore-blank-lines diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,3 @@ -hello world +hello +world goodbye world Test hunk offsets adjustments with --ignore-blank-lines $ hg revert -aC reverting foo $ printf '\nb\nx\nd\n' > a $ printf 'b\ny\nd\n' > b $ hg add a b $ hg ci -m add $ hg cat -r . a > b $ hg cat -r . b > a $ hg diff -B --nodates a > ../diffa $ cat ../diffa diff -r 0e66aa54f318 a --- a/a +++ b/a @@ -1,4 +1,4 @@ b -x +y d $ hg diff -B --nodates b > ../diffb $ cat ../diffb diff -r 0e66aa54f318 b --- a/b +++ b/b @@ -1,3 +1,3 @@ b -y +x d $ hg revert -aC reverting a reverting b $ hg import --no-commit ../diffa applying ../diffa $ hg revert -aC reverting a $ hg import --no-commit ../diffb applying ../diffb $ hg revert -aC reverting b