view tests/test-filelog.py.out @ 34002:2ad028635ccd

util: use ~ as a suffix for a temp file in the same directory as a source file

Tools like Buck have patterns to ignore the creation of files (in the working
copy) that match certain patterns:

https://github.com/facebook/buck/blob/39278a4f0701c5239eae148968dc1ed4cc8661f7/src/com/facebook/buck/cli/Main.java#L259-L299

When Buck sees a new source file (as reported by Watchman), it has to invalidate
a number of caches associated with the directory that contains the file.
Using a standard suffix, such as `~`, would make it easier for Buck and others
to filter out these types of file creation events.

The other uses of `tempfile.mkstemp()` in Hg do not appear to be problematic
because they (generally speaking) do not specify the `dir` parameter, so the
new file is created in the system-appropriate temp directory, which is outside
the working copy.

Test Plan:
`make tests`

Differential Revision: https://phab.mercurial-scm.org/D468

ERROR: FIXME: This is a known failure of filelog.size for data starting with \1\n
OK.