The following patch works around the bug in grep which makes

	grep '[a-c]'

match "B".  Note, this is a bug in grep caused by a bug in the
standards which do not provide interfaces to get the necessary
information.  This patch as correct as grep was before (multibyte char
handling is not 100% correct but that cannot be solved now), future
changes might increase the speed a bit.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
--- grep-2.4.2/src/dfa.c-old	Sat Aug 19 17:55:05 2000
+++ grep-2.4.2/src/dfa.c	Sat Aug 19 17:55:11 2000
@@ -743,6 +743,7 @@ lex (void)
 	      else
 		c2 = c;
 
+#if 0
 	      lo[0] = c;  lo[1] = '\0';
 	      hi[0] = c2; hi[1] = '\0';
 	      for (c = 0; c < NOTCHAR; c++)
@@ -761,6 +762,37 @@ lex (void)
 			}
 		    }
 		}
+#else
+	      {
+		char expr[6] = { '[', c, '-', c2, ']', '\0' };
+		regex_t re;
+
+		if (regcomp (&re, expr, case_fold ? REG_ICASE : 0)
+		    == REG_NOERROR)
+		  {
+		    for (c = 0; c < NOTCHAR; ++c)
+		      {
+			char buf[2] = { c, '\0' };
+			regmatch_t mat;
+
+			if (regexec (&re, buf, 1, &mat, 0) == REG_NOERROR
+			    && mat.rm_so == 0 && mat.rm_eo == 1)
+			  {
+			    setbit (c, ccl);
+			    if (case_fold)
+			      {
+				if (ISUPPER (c))
+				  setbit (tolower (c), ccl);
+				else if (ISLOWER (c))
+				  setbit (toupper (c), ccl);
+			      }
+			  }
+		      }
+
+		    regfree (&re);
+		  }
+	      }
+#endif
 
 	    skip:
 	      ;
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~