From @dgl

Matching unexpectedly fails when the string is longer than I32. The
following fixes it, but I see a lot of I32 in the regexp engine itself so
this might be masking other issues (see also RT #72784).

diff --git a/pp_hot.c b/pp_hot.c
index 89165d9..662b908 100644
--- a/pp_hot.c
+++ b/pp_hot.c
@@ -1303,7 +1303,7 @@ PP(pp_match)
        rx = PM_GETRE(pm);
     }

-    if (RX_MINLEN(rx) > (I32)len)
+    if ((STRLEN)RX_MINLEN(rx) > len)
        goto failure;

     truebase = t = s;

$ perl -Mre=debug -le'$a="x"x 1048576; $b.=$a for 1 .. 2047; $b.="y"; print
length $b; print $b =~ /y/ ? "Matched" : "No match"'
Compiling REx "y"
Final program​:
  1​: EXACT <y> (3)
  3​: END (0)
anchored "y" at 0 (checking anchored isall) minlen 1
2146435073
Guessing start of match in sv for REx "y" against
"xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"...
Found anchored substr "y" at offset 2146435072...
Starting position does not contradict /^/m...
Guessed​: match at offset 2146435072
Matched
Freeing REx​: "y"

$ perl -Mre=debugcolor -le'$a="x"x 1048576; $b.=$a for 1 .. 2048; $b.="y";
print length $b; print $b =~ /y/ ? "Matched" : "No match"'
Compiling REx "y"
Final program​:
  1​: EXACT <y> (3)
  3​: END (0)
anchored "y" at 0 (checking anchored isall) minlen 1
2147483649
No match
Freeing REx​: "y"

From @cpansprout

On Sun May 06 11​:19​:53 2012, dgl wrote​:

Matching unexpectedly fails when the string is longer than I32. The
following fixes it, but I see a lot of I32 in the regexp engine itself so
this might be masking other issues (see also RT #72784).

diff --git a/pp_hot.c b/pp_hot.c
index 89165d9..662b908 100644
--- a/pp_hot.c
+++ b/pp_hot.c
@​@​ -1303,7 +1303,7 @​@​ PP(pp_match)
rx = PM_GETRE(pm);
}

- if (RX_MINLEN(rx) > (I32)len)
+ if ((STRLEN)RX_MINLEN(rx) > len)
goto failure;

 truebase = t = s;

I have gone through the regexp engine and change any uses of I32 that
hold lengths of the string being matched against.

See the commits leading up to merge commit ed56dbc, in particular
389ecb5 which is similar to your proposed patch.

--

Father Chrysostomos

The RT System itself - Status changed from 'new' to 'open'

@cpansprout - Status changed from 'open' to 'resolved'