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fix for failure to match $foo =~ /(?i)/ (from Ilya Zakharevich)
[perl5.git] / regexec.c
index 8f5278c..cd3df47 100644 (file)
--- a/regexec.c
+++ b/regexec.c
@@ -1434,9 +1434,14 @@ Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char *
        /* we have /x+whatever/ */
        /* it must be a one character string (XXXX Except UTF?) */
        char ch = SvPVX(prog->anchored_substr)[0];
+#ifdef DEBUGGING
+       int did_match = 0;
+#endif
+
        if (UTF) {
            while (s < strend) {
                if (*s == ch) {
+                   DEBUG_r( did_match = 1 );
                    if (regtry(prog, s)) goto got_it;
                    s += UTF8SKIP(s);
                    while (s < strend && *s == ch)
@@ -1448,6 +1453,7 @@ Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char *
        else {
            while (s < strend) {
                if (*s == ch) {
+                   DEBUG_r( did_match = 1 );
                    if (regtry(prog, s)) goto got_it;
                    s++;
                    while (s < strend && *s == ch)
@@ -1456,6 +1462,9 @@ Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char *
                s++;
            }
        }
+       DEBUG_r(did_match ||
+               PerlIO_printf(Perl_debug_log,
+                             "Did not find anchored character...\n"));
     }
     /*SUPPRESS 560*/
     else if (prog->anchored_substr != Nullsv
@@ -1471,6 +1480,9 @@ Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char *
                          -(I32)(CHR_SVLEN(must)
                                 - (SvTAIL(must) != 0) + back_min));
        char *last1;            /* Last position checked before */
+#ifdef DEBUGGING
+       int did_match = 0;
+#endif
 
        if (s > PL_bostr)
            last1 = HOPc(s, -1);
@@ -1489,6 +1501,7 @@ Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char *
                 : (s = fbm_instr((unsigned char*)HOP(s, back_min),
                                  (unsigned char*)strend, must, 
                                  PL_multiline ? FBMrf_MULTILINE : 0))) ) {
+           DEBUG_r( did_match = 1 );
            if (HOPc(s, -back_max) > last1) {
                last1 = HOPc(s, -back_min);
                s = HOPc(s, -back_max);
@@ -1514,6 +1527,14 @@ Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char *
                }
            }
        }
+       DEBUG_r(did_match ||
+               PerlIO_printf(Perl_debug_log, "Did not find %s substr `%s%.*s%s'%s...\n",
+                             ((must == prog->anchored_substr)
+                              ? "anchored" : "floating"),
+                             PL_colors[0],
+                             (int)(SvCUR(must) - (SvTAIL(must)!=0)),
+                             SvPVX(must),
+                             PL_colors[1], (SvTAIL(must) ? "$" : "")));
        goto phooey;
     }
     else if ((c = prog->regstclass)) {
@@ -1522,6 +1543,7 @@ Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char *
            strend = HOPc(strend, -(minlen - 1));
        if (find_byclass(prog, c, s, strend, startpos, 0))
            goto got_it;
+       DEBUG_r(PerlIO_printf(Perl_debug_log, "Contradicts stclass...\n"));
     }
     else {
        dontbother = 0;
@@ -1554,7 +1576,12 @@ Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char *
                        last = strend;  /* matching `$' */
                }
            }
-           if (last == NULL) goto phooey; /* Should not happen! */
+           if (last == NULL) {
+               DEBUG_r(PerlIO_printf(Perl_debug_log,
+                                     "%sCan't trim the tail, match fails (should not happen)%s\n",
+                                     PL_colors[4],PL_colors[5]));
+               goto phooey; /* Should not happen! */
+           }
            dontbother = strend - last + prog->float_min_offset;
        }
        if (minlen && (dontbother < minlen))
@@ -1616,6 +1643,8 @@ got_it:
     return 1;
 
 phooey:
+    DEBUG_r(PerlIO_printf(Perl_debug_log, "%sMatch failed%s\n",
+                         PL_colors[4],PL_colors[5]));
     if (PL_reg_eval_set)
        restore_pos(aTHXo_ 0);
     return 0;