check-code: catch Python 'is' comparing number or string literals
The Python 'is' operator compares object identity, so it should
definitely not be applied to string or number literals, which Python
implementations are free to represent with a temporary object.
This should catch the following kinds of bogus expressions (examples):
x is 'foo' x is not 'foo'
x is "bar" x is not "bar"
x is 42 x is not 42
x is -36 x is not -36
As originally proposed by Martin Geisler, amended with catching
negative numbers.
$ hg init a
$ cd a
$ echo a > a
$ hg add -n
adding a
$ hg st
? a
$ hg add
adding a
$ hg st
A a
$ hg forget a
$ hg add
adding a
$ hg st
A a
$ echo b > b
$ hg add -n b
$ hg st
A a
? b
$ hg add b
$ hg st
A a
A b
should fail
$ hg add b
b already tracked!
$ hg st
A a
A b
$ hg ci -m 0 --traceback
should fail
$ hg add a
a already tracked!
$ echo aa > a
$ hg ci -m 1
$ hg up 0
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ echo aaa > a
$ hg ci -m 2
created new head
$ hg merge
merging a
warning: conflicts during merge.
merging a failed!
0 files updated, 0 files merged, 0 files removed, 1 files unresolved
use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
[1]
$ hg st
M a
? a.orig
should fail
$ hg add a
a already tracked!
$ hg st
M a
? a.orig
$ hg resolve -m a
$ hg ci -m merge
Issue683: peculiarity with hg revert of an removed then added file
$ hg forget a
$ hg add a
$ hg st
? a.orig
$ hg rm a
$ hg st
R a
? a.orig
$ echo a > a
$ hg add a
$ hg st
M a
? a.orig
$ hg add c && echo "unexpected addition of missing file"
c: No such file or directory
[1]
$ echo c > c
$ hg add d c && echo "unexpected addition of missing file"
d: No such file or directory
[1]
$ hg st
M a
A c
? a.orig