Trap OSError when deleting env vars
On the other OS, it seems that case insensitivity for
environment vars can bite users when using some unknown
combination of python 2.4.1 and win2kSP4+minsys (and
probably other vversions of these softwares).
The best way to avoid problems in those weird cases is to
ignore OSError exception during env var deletion.
+ hg init
+ hg add file1 file2
+ hg commit -m added file1 and file2 -d 0 0 -u user
+ hg commit -m changed file1 -d 0 0 -u user
+ hg -q log
1:3aa14bbc23d90e3f8b5b639b4a43d76509bae76c
0:8633637036c18f021d771208e16ae3508ab81d28
+ hg id
3aa14bbc23d9 tip
+ hg update -C 0
+ hg id
8633637036c1
+ hg id
8633637036c1+
+ hg revert
+ hg diff
+ hg status
+ hg id
8633637036c1
+ hg update
+ hg diff
+ hg status
+ hg id
3aa14bbc23d9 tip
+ hg update -C 0
+ hg update
merge: warning: conflicts during merge
merging file1
merging file1 failed!
+ hg diff
diff -r 3aa14bbc23d9 file1
--- a/file1
+++ b/file1
@@ -1,2 +1,6 @@
added file1
+<<<<<<<
+changed file1 different
+=======
changed file1
+>>>>>>>
+ hg status
M file1
+ hg id
3aa14bbc23d9+ tip
+ hg revert
+ hg diff
FIXME: This is a known bug:
+ hg status
+ hg id
3aa14bbc23d9 tip
+ hg revert -r tip
+ hg diff
+ hg status
+ hg id
3aa14bbc23d9 tip
+ hg update -C
+ hg diff
+ hg status
+ hg id
3aa14bbc23d9 tip