diff options
| author | Paul Eggert <eggert@cs.ucla.edu> | 2012-07-08 16:00:38 -0700 |
|---|---|---|
| committer | Paul Eggert <eggert@cs.ucla.edu> | 2012-07-08 16:00:38 -0700 |
| commit | ab531b66f3a676ef047300f5201daa52993099b9 (patch) | |
| tree | d7a199eb5c58195e2d17f6c2765ebb5f6a0ea8b3 /src/systime.h | |
| parent | 0ccb0b098349c987e35ee1b2ec795f24a743a4e0 (diff) | |
| download | emacs-ab531b66f3a676ef047300f5201daa52993099b9.tar.gz | |
* systime.h (EMACS_SUB_TIME): Clarify behavior with unsigned time_t.
See <http://bugs.gnu.org/11825#29>.
Diffstat (limited to 'src/systime.h')
| -rw-r--r-- | src/systime.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/src/systime.h b/src/systime.h index 938083a5ffc..a03630cf936 100644 --- a/src/systime.h +++ b/src/systime.h @@ -80,7 +80,8 @@ typedef unsigned long Time; #define EMACS_GET_TIME(time) gettime (&(time)) /* Put into DEST the result of adding SRC1 to SRC2, or of subtracting - SRC2 from SRC1. On overflow, store an extremal value. */ + SRC2 from SRC1. On overflow, store an extremal value: ergo, if + time_t is unsigned, return 0 if the true answer would be negative. */ #define EMACS_ADD_TIME(dest, src1, src2) ((dest) = timespec_add (src1, src2)) #define EMACS_SUB_TIME(dest, src1, src2) ((dest) = timespec_sub (src1, src2)) |