view tests/test-diff-change.t @ 18063:34a1a639d835

revset.children: ignore rev numbers that are too low

This replaces unnecessary parentrevs() calls with calculating min(parentset).
Even though the min operation is O(size of parentset), since parentrevs is
relatively expensive, this tradeoff almost always works in our favour. In a
repository with over 400,000 changesets, hg perfrevset "children(X)" takes:

       Set X       Before    After
       -1           0.51s    0.06s
    -1000:          0.55s    0.08s
   -10000:          0.56s    0.10s
  -100000:          0.60s    0.25s
  -100000:-99000    0.55s    0.19s
        0:100000    0.60s    0.61s
      all()         0.72s    0.74s

The relative performance is similar for Mercurial's own repository -- several
times faster in most cases, slightly slower for revisions close to 0 and
all().

Testing diff --change

  $ hg init a
  $ cd a

  $ echo "first" > file.txt
  $ hg add file.txt
  $ hg commit -m 'first commit' # 0

  $ echo "second" > file.txt
  $ hg commit -m 'second commit' # 1

  $ echo "third" > file.txt
  $ hg commit -m 'third commit' # 2

  $ hg diff --nodates --change 1
  diff -r 4bb65dda5db4 -r e9b286083166 file.txt
  --- a/file.txt
  +++ b/file.txt
  @@ -1,1 +1,1 @@
  -first
  +second

  $ hg diff --change e9b286083166
  diff -r 4bb65dda5db4 -r e9b286083166 file.txt
  --- a/file.txt	Thu Jan 01 00:00:00 1970 +0000
  +++ b/file.txt	Thu Jan 01 00:00:00 1970 +0000
  @@ -1,1 +1,1 @@
  -first
  +second

Test dumb revspecs (issue3474)

  $ hg diff -r 2:2
  $ hg diff -r "2 and 1"
  abort: empty revision range
  [255]

Testing diff --change when merge:

  $ for i in 1 2 3 4 5 6 7 8 9 10; do
  >    echo $i >> file.txt
  > done
  $ hg commit -m "lots of text" # 3

  $ sed -e 's,^2$,x,' file.txt > file.txt.tmp
  $ mv file.txt.tmp file.txt
  $ hg commit -m "change 2 to x" # 4

  $ hg up -r 3
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ sed -e 's,^8$,y,' file.txt > file.txt.tmp
  $ mv file.txt.tmp file.txt
  $ hg commit -m "change 8 to y"
  created new head

  $ hg up -C -r 4
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg merge -r 5
  merging file.txt
  0 files updated, 1 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg commit -m "merge 8 to y" # 6

  $ hg diff --change 5
  diff -r ae119d680c82 -r 9085c5c02e52 file.txt
  --- a/file.txt	Thu Jan 01 00:00:00 1970 +0000
  +++ b/file.txt	Thu Jan 01 00:00:00 1970 +0000
  @@ -6,6 +6,6 @@
   5
   6
   7
  -8
  +y
   9
   10

must be similar to 'hg diff --change 5':

  $ hg diff -c 6
  diff -r 273b50f17c6d -r 979ca961fd2e file.txt
  --- a/file.txt	Thu Jan 01 00:00:00 1970 +0000
  +++ b/file.txt	Thu Jan 01 00:00:00 1970 +0000
  @@ -6,6 +6,6 @@
   5
   6
   7
  -8
  +y
   9
   10

  $ cd ..