Remove INT_ADD_WRAPV bug workarounds

* src/alloc.c (free_cons):
* src/casefiddle.c (do_casify_multibyte_string):
* src/editfns.c (styled_format):
* src/image.c (png_load_body):
Remove recent workarounds for INT_ADD_WRAPV bugs since
the bugs have been fixed (Bug#37006).

4 files changed, 8 insertions, 18 deletions

diff --git a/src/alloc.c b/src/alloc.c
index 0548a09cb8b..bb8e97f8737 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -2543,10 +2543,7 @@ free_cons (struct Lisp_Cons *ptr)
   ptr->u.s.u.chain = cons_free_list;
   ptr->u.s.car = dead_object ();
   cons_free_list = ptr;
-  /* Use a temporary signed variable, since otherwise INT_ADD_WRAPV
-     might incorrectly return non-zero.  */
-  int incr = sizeof *ptr;
-  if (INT_ADD_WRAPV (consing_until_gc, incr, &consing_until_gc))
+  if (INT_ADD_WRAPV (consing_until_gc, sizeof *ptr, &consing_until_gc))
     consing_until_gc = INTMAX_MAX;
   gcstat.total_free_conses++;
 }
diff --git a/src/casefiddle.c b/src/casefiddle.c
index 741973e40af..ee292dda9b3 100644
--- a/src/casefiddle.c
+++ b/src/casefiddle.c
@@ -265,11 +265,8 @@ do_casify_multibyte_string (struct casing_context *ctx, Lisp_Object obj)
 
   ptrdiff_t size = SCHARS (obj), n;
   USE_SAFE_ALLOCA;
-  /* Use a temporary signed variable, since otherwise INT_ADD_WRAPV
-     might incorrectly return non-zero.  */
-  ptrdiff_t casing_str_buf_size = sizeof (struct casing_str_buf);
   if (INT_MULTIPLY_WRAPV (size, MAX_MULTIBYTE_LENGTH, &n)
-      || INT_ADD_WRAPV (n, casing_str_buf_size, &n))
+      || INT_ADD_WRAPV (n, sizeof (struct casing_str_buf), &n))
     n = PTRDIFF_MAX;
   unsigned char *dst = SAFE_ALLOCA (n);
   unsigned char *dst_end = dst + n;
diff --git a/src/editfns.c b/src/editfns.c
index 19bbfdcd478..1b33f397110 100644
--- a/src/editfns.c
+++ b/src/editfns.c
@@ -3158,14 +3158,12 @@ styled_format (ptrdiff_t nargs, Lisp_Object *args, bool message)
   /* Upper bound on number of format specs.  Each uses at least 2 chars.  */
   ptrdiff_t nspec_bound = SCHARS (args[0]) >> 1;
 
-  /* Use a temporary signed variable, since otherwise INT_ADD_WRAPV
-     might incorrectly return non-zero.  */
-  ptrdiff_t info_size = sizeof *info, alloca_size;
-  if (INT_MULTIPLY_WRAPV (nspec_bound, info_size, &info_size)
+  /* Allocate the info and discarded tables.  */
+  ptrdiff_t info_size, alloca_size;
+  if (INT_MULTIPLY_WRAPV (nspec_bound, sizeof *info, &info_size)
       || INT_ADD_WRAPV (formatlen, info_size, &alloca_size)
       || SIZE_MAX < alloca_size)
     memory_full (SIZE_MAX);
-  /* Allocate the info and discarded tables.  */
   info = SAFE_ALLOCA (alloca_size);
   /* discarded[I] is 1 if byte I of the format
      string was not copied into the output.
diff --git a/src/image.c b/src/image.c
index b37851f0963..81d8cb4e2b2 100644
--- a/src/image.c
+++ b/src/image.c
@@ -6463,6 +6463,7 @@ png_load_body (struct frame *f, struct image *img, struct png_load_context *c)
   png_uint_32 row_bytes;
   bool transparent_p;
   struct png_memory_storage tbr;  /* Data to be read */
+  ptrdiff_t nbytes;
   Emacs_Pix_Container ximg, mask_img = NULL;
 
   /* Find out what file to load.  */
@@ -6658,13 +6659,10 @@ png_load_body (struct frame *f, struct image *img, struct png_load_context *c)
   /* Number of bytes needed for one row of the image.  */
   row_bytes = png_get_rowbytes (png_ptr, info_ptr);
 
-  /* Use a temporary signed variable, since otherwise
-     INT_MULTIPLY_WRAPV might incorrectly return non-zero.  */
-  ptrdiff_t nbytes = sizeof *pixels;
-  if (INT_MULTIPLY_WRAPV (row_bytes, nbytes, &nbytes)
+  /* Allocate memory for the image.  */
+  if (INT_MULTIPLY_WRAPV (row_bytes, sizeof *pixels, &nbytes)
       || INT_MULTIPLY_WRAPV (nbytes, height, &nbytes))
     memory_full (SIZE_MAX);
-  /* Allocate memory for the image.  */
   c->pixels = pixels = xmalloc (nbytes);
   c->rows = rows = xmalloc (height * sizeof *rows);
   for (i = 0; i < height; ++i)