Signal error when reading an empty byte-code object (Bug#15405)

* lread.c (read1): signal error
* alloc.c (make_byte_code): eassert header size
(sweep_vectors): change an int to size_t

3 files changed, 14 insertions, 2 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 3f0c4196afd..a6774e30b0c 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,10 @@
+2013-09-26  Barry O'Reilly  <gundaetiapo@gmail.com>
+
+        Signal error when reading an empty byte-code object (Bug#15405)
+        * lread.c (read1): signal error
+        * alloc.c (make_byte_code): eassert header size
+        (sweep_vectors): change an int to size_t
+
 2013-09-24  Paul Eggert  <eggert@cs.ucla.edu>
 
         * dispnew.c (clear_glyph_row, copy_row_except_pointers): Use enums
diff --git a/src/alloc.c b/src/alloc.c
index ca21ba2469b..2d9828ffa79 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -2889,7 +2889,7 @@ sweep_vectors (void)
                 free_this_block = 1;
               else
                 {
-                  int tmp;
+                  size_t tmp;
                   SETUP_ON_FREE_LIST (vector, total_bytes, tmp);
                 }
             }
@@ -3132,6 +3132,8 @@ usage: (vector &rest OBJECTS)  */)
 void
 make_byte_code (struct Lisp_Vector *v)
 {
+  /* Don't allow the global zero_vector to become a byte code object. */
+  eassert(0 < v->header.size);
   if (v->header.size > 1 && STRINGP (v->u.contents[1])
       && STRING_MULTIBYTE (v->u.contents[1]))
     /* BYTECODE-STRING must have been produced by Emacs 20.2 or the
diff --git a/src/lread.c b/src/lread.c
index 017dfcb11a5..fe2b92a34b3 100644
--- a/src/lread.c
+++ b/src/lread.c
@@ -2597,7 +2597,10 @@ read1 (Lisp_Object readcharfun, int *pch, bool first_in_list)
              build them using function calls.  */
           Lisp_Object tmp;
           tmp = read_vector (readcharfun, 1);
-          make_byte_code (XVECTOR (tmp));
+          struct Lisp_Vector* vec = XVECTOR (tmp);
+          if (vec->header.size==0)
+            invalid_syntax ("Empty byte-code object");
+          make_byte_code (vec);
           return tmp;
         }
       if (c == '(')