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| author |  Flavio Toffalini | 2026-10-26 09:03:57 +0000 |
|---|---|---|
| committer |  Nikias Bassen | 2026-11-06 10:29:06 +0100 |
| commit | 1d3b54c784da260f71d885f5f560d69c211a645e (patch) | |
| tree | 6aa7b84ae67249d740bd4c43500a349e403ca2e6 /test/Makefile.am | |
| parent | 9fdbf585f47501ba19a53fd4bb382d5b533e3fdd (diff) | |
| download | libplist-1d3b54c784da260f71d885f5f560d69c211a645e.tar.gz libplist-1d3b54c784da260f71d885f5f560d69c211a645e.tar.bz2 | |
plist: fix the (sec, usec) date API round trip
plist_set_date_val stores val = sec + usec / 1000000, but
plist_get_date_val splits it with a truncating cast and fabs():
*sec = (int32_t)val;
val = fabs((val - (int64_t)val) * 1000000);
*usec = (int32_t)val;
Two results are wrong. The product is truncated, so set(5, 6) reads
back as (5, 5) - 29.3% of round trips over sec in [0, 3] come back a
microsecond short. And for a negative value, truncation toward zero
plus fabs() give a pair that does not denote the same instant:
set(-3, 250000) stores -2.75 and reads back as (-2, 750000), which the
setter would store as -1.25. Every round trip with sec < 0 and
usec != 0 is wrong.
(int32_t)val is also undefined when the stored value is outside the
int32_t range.
Round the seconds down, round the fraction to microseconds carrying
1000000 into the seconds, and clamp the seconds before converting, so
sec + usec / 1000000 == val to the microsecond with 0 <= usec <
1000000 - the convention the setter uses.
Add test/date_val.c covering fixed cases and a sweep over sec in
[-2, 2]. It fails on an unmodified tree - set(5, 6), set(-3, 250000)
and set(-1, 1) all come back as different instants - and passes with
this change, with make check at 44/44.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Arn4YaWtcQBDsQuJtyBmFP
Diffstat (limited to 'test/Makefile.am')
| -rw-r--r-- | test/Makefile.am | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/test/Makefile.am b/test/Makefile.am index 1d98349..2e2b04e 100644 --- a/test/Makefile.am +++ b/test/Makefile.am @@ -11,6 +11,7 @@ noinst_PROGRAMS = \ plist_test \ plist_test++ \ integer_set_test \ + date_val_test \ plist_btest \ plist_jtest \ plist_otest \ @@ -31,6 +32,9 @@ plist_test_LDADD = $(top_builddir)/src/libplist-2.0.la integer_set_test_SOURCES = integer_set.c integer_set_test_LDADD = $(top_builddir)/src/libplist-2.0.la +date_val_test_SOURCES = date_val.c +date_val_test_LDADD = $(top_builddir)/src/libplist-2.0.la + plist_btest_SOURCES = plist_btest.c plist_btest_LDADD = $(top_builddir)/src/libplist-2.0.la @@ -47,6 +51,7 @@ bplist_behavior_test_SOURCES = bplist_behavior_test.c bplist_behavior_test_LDADD = $(top_builddir)/src/libplist-2.0.la TESTS = \ + date_val.test \ empty.test \ small.test \ medium.test \ |