(EXTEND_BUFFER): Change order of pointer addition operations, to avoid

having the difference between pointers overflow.

diff --git a/src/regex.c b/src/regex.c
index eca78f2ab94309ec20df550e3b3c98168e49bf4e..cbc67568743fc982cc559fdff068d3846b9008d9 100644 (file)
--- a/src/regex.c
+++ b/src/regex.c
@@ -1854,8 +1854,10 @@ static int analyse_first _RE_ARGS ((re_char *p, re_char *pend,
    being larger than MAX_BUF_SIZE, then flag memory exhausted.  */
 #if __BOUNDED_POINTERS__
 # define SET_HIGH_BOUND(P) (__ptrhigh (P) = __ptrlow (P) + bufp->allocated)
-# define MOVE_BUFFER_POINTER(P) \
-  (__ptrlow (P) += incr, SET_HIGH_BOUND (P), __ptrvalue (P) += incr)
+# define MOVE_BUFFER_POINTER(P)                                        \
+  (__ptrlow (P) = new_buffer + (__ptrlow (P) - old_buffer),    \
+   SET_HIGH_BOUND (P),                                         \
+   __ptrvalue (P) = new_buffer + (__ptrvalue (P) - old_buffer))
 # define ELSE_EXTEND_BUFFER_HIGH_BOUND         \
   else                                         \
     {                                          \
@@ -1869,12 +1871,12 @@ static int analyse_first _RE_ARGS ((re_char *p, re_char *pend,
        SET_HIGH_BOUND (pending_exact);         \
     }
 #else
-# define MOVE_BUFFER_POINTER(P) (P) += incr
+# define MOVE_BUFFER_POINTER(P) ((P) = new_buffer + ((P) - old_buffer))
 # define ELSE_EXTEND_BUFFER_HIGH_BOUND
 #endif
 #define EXTEND_BUFFER()                                                        \
   do {                                                                 \
-    re_char *old_buffer = bufp->buffer;                                        \
+    unsigned char *old_buffer = bufp->buffer;                          \
     if (bufp->allocated == MAX_BUF_SIZE)                               \
       return REG_ESIZE;                                                        \
     bufp->allocated <<= 1;                                             \
@@ -1886,7 +1888,7 @@ static int analyse_first _RE_ARGS ((re_char *p, re_char *pend,
     /* If the buffer moved, move all the pointers into it.  */         \
     if (old_buffer != bufp->buffer)                                    \
       {                                                                        \
-       int incr = bufp->buffer - old_buffer;                           \
+       unsigned char *new_buffer = bufp->buffer;                       \
        MOVE_BUFFER_POINTER (b);                                        \
        MOVE_BUFFER_POINTER (begalt);                                   \
        if (fixup_alt_jump)                                             \