changectx: increase perf of walk function
When running 'hg cat -r . <file>' it was doing an expensive ctx.walk(m) which
applied the regex to every file in the manifest.
This changes changectx.walk to iterate over just the files in the regex, if no
other patterns are specified. This cuts hg cat time by 50% in our repo and
probably benefits a few other commands as well.
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 ..