Introduce chk_wmalloc function.

Two-fold benefit. Simplifies code which allocates wchar_t
arrays. Provides overflow check for the multiplication.

* lib.c (chk_wmalloc): New function.
(chk_strdup, mkstring, mkustring, upcase_str, downcase_str,
sub_str, cat_str, trim_str): Use chk_wmalloc.

* lib.h (chk_wmalloc): Declared.

* stream.c (make_string_output_stream): Use chk_wmalloc.

* utf8.c (utf8_dup_from_uc, utf8_dup_from): Likewise.

1 files changed, 2 insertions, 2 deletions

diff --git a/utf8.c b/utf8.c
index a45c1b94..a09e082b 100644
--- a/utf8.c
+++ b/utf8.c
@@ -203,7 +203,7 @@ size_t utf8_to(char *dst, const wchar_t *wsrc)
 wchar_t *utf8_dup_from_uc(const unsigned char *str)
 {
   size_t nchar = utf8_from_uc(0, str);
-  wchar_t *wstr = coerce(wchar_t *, chk_malloc(nchar * sizeof *wstr));
+  wchar_t *wstr = chk_wmalloc(nchar);
   utf8_from_uc(wstr, str);
   return wstr;
 }
@@ -211,7 +211,7 @@ wchar_t *utf8_dup_from_uc(const unsigned char *str)
 wchar_t *utf8_dup_from(const char *str)
 {
   size_t nchar = utf8_from(0, str);
-  wchar_t *wstr = coerce(wchar_t *, chk_malloc(nchar * sizeof *wstr));
+  wchar_t *wstr = chk_wmalloc(nchar);
   utf8_from(wstr, str);
   return wstr;
 }