From 58c834052f0985406919de157297e0c340c5b2ed Mon Sep 17 00:00:00 2001

From: ph10 <ph10@2f5784b3-3f2a-0410-8824-cb99058d5e15>

Date: Fri, 8 Aug 2014 15:22:51 +0000

Subject: [PATCH 2/2] Fix compile-time loop for recursive reference within a

 group with an indefinite repeat.

MIME-Version: 1.0

Content-Type: text/plain; charset=UTF-8

Content-Transfer-Encoding: 8bit

git-svn-id: svn://vcs.exim.org/pcre/code/trunk@1498 2f5784b3-3f2a-0410-8824-cb99058d5e15

Signed-off-by: Petr Písař <ppisar@redhat.com>

Petr Pisar: Ported to 8.32.

Signed-off-by: Petr Písař <ppisar@redhat.com>

---

 pcre_compile.c       | 17 +++++++----------

 testdata/testinput1  |  6 ++++++

 testdata/testoutput1 | 10 ++++++++++

 3 files changed, 23 insertions(+), 10 deletions(-)

diff --git a/pcre_compile.c b/pcre_compile.c

index ce72527..86cd0c8 100644

--- a/pcre_compile.c

+++ b/pcre_compile.c

@@ -2398,6 +2398,7 @@ for (code = first_significant_code(code + PRIV(OP_lengths)[*code], TRUE);

   if (c == OP_RECURSE)

     {

     const pcre_uchar *scode = cd->start_code + GET(code, 1);

+    const pcre_uchar *endgroup = scode;

     BOOL empty_branch;

     /* Test for forward reference or uncompleted reference. This is disabled

@@ -2412,20 +2413,16 @@ for (code = first_significant_code(code + PRIV(OP_lengths)[*code], TRUE);

       if (GET(scode, 1) == 0) return TRUE;    /* Unclosed */

       }

-    /* If we are scanning a completed pattern, there are no forward references 

-    and all groups are complete. We need to detect whether this is a recursive 

-    call, as otherwise there will be an infinite loop. If it is a recursion,

-    just skip over it. Simple recursions are easily detected. For mutual 

-    recursions we keep a chain on the stack. */ 

+    /* If the reference is to a completed group, we need to detect whether this

+    is a recursive call, as otherwise there will be an infinite loop. If it is

+    a recursion, just skip over it. Simple recursions are easily detected. For

+    mutual recursions we keep a chain on the stack. */

+    do endgroup += GET(endgroup, 1); while (*endgroup == OP_ALT);

+    if (code >= scode && code <= endgroup) continue;  /* Simple recursion */

     else

       {  

       recurse_check *r = recurses;

-      const pcre_uchar *endgroup = scode;

-       

-      do endgroup += GET(endgroup, 1); while (*endgroup == OP_ALT);

-      if (code >= scode && code <= endgroup) continue;  /* Simple recursion */

-      

       for (r = recurses; r != NULL; r = r->prev)

         if (r->group == scode) break;

       if (r != NULL) continue;   /* Mutual recursion */

diff --git a/testdata/testinput1 b/testdata/testinput1

index 3e1061e..c45e1ba 100644

--- a/testdata/testinput1

+++ b/testdata/testinput1

@@ -4967,6 +4967,12 @@ however, we need the complication for Perl. ---/

 /((?(R1)a+|(?1)b))/

     aaaabcde

+    

+/((?(R)a|(?1)))*/

+    aaa

+

+/((?(R)a|(?1)))+/

+    aaa

 /a(*:any 

 name)/K

diff --git a/testdata/testoutput1 b/testdata/testoutput1

index 5015448..f0eae49 100644

--- a/testdata/testoutput1

+++ b/testdata/testoutput1

@@ -8271,6 +8271,16 @@ MK: M

     aaaabcde

  0: aaaab

  1: aaaab

+    

+/((?(R)a|(?1)))*/

+    aaa

+ 0: aaa

+ 1: a

+

+/((?(R)a|(?1)))+/

+    aaa

+ 0: aaa

+ 1: a

 /a(*:any 

 name)/K

-- 

2.5.5