time: Use struct alloc_buffer in __tzfile_read

The computation of tzspec_len is moved in front of the total_size
computation, so that the allocation size computation and the
suballocations are next to each other.  Also add an assert that
tzspec_len is positive when it is actually used later.

1 files changed, 5 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index 82604298de..bc1b17ffa7 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2019-02-03  Florian Weimer  <fweimer@redhat.com>
+
+	* time/tzfile.c (__tzfile_read): Use struct alloc_buffer and its
+	implicit overflow checks.
+
 2019-02-03  Aurelien Jarno  <aurelien@aurel32.net>
 
 	* stdlib/isomac.c: Include <unistd.h>.