[PATCH] dfa: small fixes to single-byte range computation

[Paolo Bonzini]

* src/dfa.c (parse_bracket_exp): Do not call regexec with an invalid
subject.  Move declarations before all statements.
---
 src/dfa.c |   18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/src/dfa.c b/src/dfa.c
index eefc817..a78e760 100644
--- a/src/dfa.c
+++ b/src/dfa.c
@@ -1104,6 +1104,11 @@ parse_bracket_exp (void)
             }
           else
             {
+              /* Defer to the system regex library about the meaning
+                 of range expressions.  */
+              regex_t re;
+              char pattern[6] = { '[', 0, '-', 0, ']', 0 };
+              char subject[2] = { 0, 0 };
               c1 = c;
               if (case_fold)
                 {
@@ -1111,17 +1116,16 @@ parse_bracket_exp (void)
                   c2 = tolower (c2);
                 }
 
-              /* Defer to the system regex library about the meaning
-                 of range expressions.  */
-              regex_t re;
-              char pattern[6] = { '[', c1, '-', c2, ']', 0 };
-              char subject[2] = { 0, 0 };
+              pattern[1] = c1;
+              pattern[3] = c2;
               regcomp (&re, pattern, REG_NOSUB);
               for (c = 0; c < NOTCHAR; ++c)
                 {
+                  if ((case_fold && isupper (c)) ||
+                      (MB_CUR_MAX > 1 && btowc (c) == WEOF))
+                    continue;
                   subject[0] = c;
-                  if (!(case_fold && isupper (c))
-                      && regexec (&re, subject, 0, NULL, 0) != REG_NOMATCH)
+                  if (regexec (&re, subject, 0, NULL, 0) != REG_NOMATCH)
                     setbit_case_fold_c (c, ccl);
                 }
               regfree (&re);
-- 
1.7.9.3