* Makefile, NEWS, newtzset.3: Mention this.
* localtime.c (FREE_PRESERVES_ERRNO):
Default to 1 if 'free' is known to preserve errno, 0 otherwise.
(tzfree): Preserve errno if 'free' does not.
---
Makefile | 2 ++
NEWS | 2 ++
localtime.c | 15 +++++++++++++++
newtzset.3 | 4 ++++
4 files changed, 23 insertions(+)
diff --git a/Makefile b/Makefile
index 0fe8a9f8..0d33fa17 100644
--- a/Makefile
+++ b/Makefile
@@ -239,6 +239,8 @@ LDLIBS=
# -DEPOCH_OFFSET=N if the 'time' function returns a value N greater
# than what POSIX specifies, assuming local time is UT.
# For example, N is 252460800 on AmigaOS.
+# -DFREE_PRESERVES_ERRNO=[01] if the 'free' function munges or preserves errno
+# (default is guessed)
# -DHAVE_DECL_ASCTIME_R=0 if <time.h> does not declare asctime_r
# on POSIX platforms predating POSIX.1-2024
# -DHAVE_DECL_ENVIRON if <unistd.h> declares 'environ'
diff --git a/NEWS b/NEWS
index 1ed9b2eb..a9b2d321 100644
--- a/NEWS
+++ b/NEWS
@@ -93,6 +93,8 @@ Unreleased, experimental changes
option is incompatible with POSIX.1-2024 and earlier. It also
costs CPU time and memory.
+ tzfree now preserves errno, consistently with POSIX.1-2024 'free'.
+
tzcode now uses mempcpy if available, guessing its availability.
Compile with -DHAVE_MEMPCPY=1 or 0 to override the guess.
diff --git a/localtime.c b/localtime.c
index b85941f2..46acf3bd 100644
--- a/localtime.c
+++ b/localtime.c
@@ -2061,10 +2061,25 @@ tzalloc(char const *name)
return sp;
}
+#ifndef FREE_PRESERVES_ERRNO
+# if ((defined _POSIX_VERSION && 202405 <= _POSIX_VERSION) \
+ || (defined __GLIBC__ && 2 < __GLIBC__ + (33 <= __GLIBC_MINOR__)) \
+ || defined __OpenBSD__ || defined __sun)
+# define FREE_PRESERVES_ERRNO 1
+# else
+# define FREE_PRESERVES_ERRNO 0
+# endif
+#endif
+
void
tzfree(timezone_t sp)
{
+ int err;
+ if (!FREE_PRESERVES_ERRNO)
+ err = errno;
free(sp);
+ if (!FREE_PRESERVES_ERRNO)
+ errno = err;
}
/*
diff --git a/newtzset.3 b/newtzset.3
index 3801ab1b..028cfd25 100644
--- a/newtzset.3
+++ b/newtzset.3
@@ -379,6 +379,10 @@ If successful, the
function returns a nonnull pointer to the newly allocated object.
Otherwise, it returns a null pointer and sets
.IR errno .
+The
+.B tzfree
+function does not modify
+.IR errno .
.SH ERRORS
.TP
.B EOVERFLOW
--
2.51.0
