(str_cmpchar_id): Check the byte sequence for

composition more rigidly.
(Fcompose_string): Allow DEL to be composed.  Signal error if STR
contains an invalid multibyte sequence.

1 files changed, 13 insertions, 3 deletions

diff --git a/src/charset.c b/src/charset.c
index 41b90189f1d..a96d39b4a56 100644
--- a/src/charset.c
+++ b/src/charset.c
@@ -1417,7 +1417,12 @@ str_cmpchar_id (str, len)
     p = str + 1;
     while (p < endp)
       {
-        if (embedded_rule) p++;
+        if (embedded_rule)
+          {
+            p++;
+            if (p >= endp)
+              return -1;
+          }
         /* No need of checking if *P is 0xA0 because
            BYTES_BY_CHAR_HEAD (0x80) surely returns 2.  */
         p += BYTES_BY_CHAR_HEAD (*p - 0x20);
@@ -1719,7 +1724,7 @@ DEFUN ("compose-string", Fcompose_string, Scompose_string,
   i = 1;
   while (p < pend)
     {
-      if (*p < 0x20 || *p == 127) /* control code */
+      if (*p < 0x20) /* control code */
         error ("Invalid component character: %d", *p);
       else if (*p < 0x80)       /* ASCII */
         {
@@ -1740,6 +1745,8 @@ DEFUN ("compose-string", Fcompose_string, Scompose_string,
             error ("Can't compose a rule-based composition character");
           ptemp = p;
           while (! CHAR_HEAD_P (*p)) p++;
+          if (str_cmpchar_id (ptemp - 1, p - ptemp + 1) < 0)
+            error ("Can't compose an invalid composition character");
           if (i + (p - ptemp) >= MAX_LENGTH_OF_MULTI_BYTE_FORM)
             error ("Too long string to be composed: %s", XSTRING (str)->data);
           bcopy (ptemp, buf + i, p - ptemp);
@@ -1749,7 +1756,10 @@ DEFUN ("compose-string", Fcompose_string, Scompose_string,
         {
           /* Add 0x20 to the base leading-code, keep the remaining
              bytes unchanged.  */
-          len = BYTES_BY_CHAR_HEAD (*p);
+          int c = STRING_CHAR_AND_CHAR_LENGTH (p, pend - p, len);
+
+          if (len <= 1 || ! CHAR_VALID_P (c, 0))
+            error ("Can't compose an invalid character");
           if (i + len >= MAX_LENGTH_OF_MULTI_BYTE_FORM)
             error ("Too long string to be composed: %s", XSTRING (str)->data);
           bcopy (p, buf + i, len);