[PATCH] git-am: flag suspiciously old or futuristic commits

The linux kernel repository has some commits in it with dates from the year 1970 and also 2030 (and possibly others). We probably shouldi warn people when the dates look suspect.

For commits in the future, note that a committer in Australia could commit on New Years Day, and send it to a maintainer in North America and that would trip the notification on the maintainer's New Years Eve. But that is unlikely, and the note is still correct; that the commit is from a future year.

For commits in the past, I chose a somewhat arbitrary 30 year limit, which will allow stuff from post 1985; the thought being that someone might want to import an old repo into git from some other SCM. We could alternatively set it to 5, which would then catch computers with a dead CMOS battery, at the risk of pestering the hypothetical museum curator of old bits.

Sample output:

paul@builder:~/git/linux-head$ grep Date: *patch future.patch:Date: Sat, 18 Jul 2037 21:22:19 -0400 past.patch:Date: Sat, 18 Jul 1977 21:22:19 -0400

paul@builder:~/git/linux-head$ git am future.patch
note: commit is from future year 2037.
Applying: arch/sh: make heartbeat driver explicitly non-modular
paul@builder:~/git/linux-head$ git reset --hard HEAD~ > /dev/null
paul@builder:~/git/linux-head$ git am past.patch
note: commit is from implausibly old year 1977.
Applying: arch/sh: make heartbeat driver explicitly non-modular
paul@builder:~/git/linux-head$

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
---
 git-am.sh | 15 +++++++++++++++
 1 file changed, 15 insertions(+)