From 93c413c5fac105d90f77ab5d03e31e0f64fc6142 Mon Sep 17 00:00:00 2001

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

Date: Tue, 27 May 2014 13:18:31 +0000

Subject: [PATCH] Fix empty-matching possessive zero-repeat groups bug.

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git-svn-id: svn://vcs.exim.org/pcre/code/trunk@1478 2f5784b3-3f2a-0410-8824-cb99058d5e15

Petr Pisar: Ported to 8.33.

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

---

 pcre_exec.c          | 41 ++++++++++++++++++++++++++---------------

 testdata/testinput1  |  9 +++++++++

 testdata/testinput8  |  6 ++++++

 testdata/testoutput1 | 12 ++++++++++++

 testdata/testoutput8 |  8 ++++++++

 5 files changed, 61 insertions(+), 15 deletions(-)

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

index ab76d02..481e899 100644

--- a/pcre_exec.c

+++ b/pcre_exec.c

@@ -1169,10 +1169,15 @@ for (;;)

         if (rrc == MATCH_KETRPOS)

           {

           offset_top = md->end_offset_top;

-          eptr = md->end_match_ptr;

           ecode = md->start_code + code_offset;

           save_capture_last = md->capture_last;

           matched_once = TRUE;

+          if (eptr == md->end_match_ptr)   /* Matched an empty string */

+            {

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

+            break;

+            }  

+          eptr = md->end_match_ptr;

           continue;

           }

@@ -1242,9 +1247,14 @@ for (;;)

       if (rrc == MATCH_KETRPOS)

         {

         offset_top = md->end_offset_top;

-        eptr = md->end_match_ptr;

         ecode = md->start_code + code_offset;

         matched_once = TRUE;

+        if (eptr == md->end_match_ptr)  /* Matched an empty string */

+          {

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

+          break;

+          }  

+        eptr = md->end_match_ptr;

         continue;

         }

@@ -1976,7 +1986,7 @@ for (;;)

     case OP_KETRMAX:

     case OP_KETRPOS:

     prev = ecode - GET(ecode, 1);

-

+    

     /* If this was a group that remembered the subject start, in order to break

     infinite repeats of empty string matches, retrieve the subject start from

     the chain. Otherwise, set it NULL. */

@@ -2001,7 +2011,7 @@ for (;;)

       md->start_match_ptr = mstart;

       RRETURN(MATCH_MATCH);         /* Sets md->mark */

       }

-

+      

     /* For capturing groups we have to check the group number back at the start

     and if necessary complete handling an extraction by setting the offsets and

     bumping the high water mark. Whole-pattern recursion is coded as a recurse

@@ -2061,6 +2071,18 @@ for (;;)

         }

       }

+    /* OP_KETRPOS is a possessive repeating ket. Remember the current position,

+    and return the MATCH_KETRPOS. This makes it possible to do the repeats one

+    at a time from the outer level, thus saving stack. This must precede the 

+    empty string test - in this case that test is done at the outer level. */

+

+    if (*ecode == OP_KETRPOS)

+      {

+      md->end_match_ptr = eptr;

+      md->end_offset_top = offset_top;

+      RRETURN(MATCH_KETRPOS);

+      }

+

     /* For an ordinary non-repeating ket, just continue at this level. This

     also happens for a repeating ket if no characters were matched in the

     group. This is the forcible breaking of infinite loops as implemented in

@@ -2083,17 +2105,6 @@ for (;;)

       break;

       }

-    /* OP_KETRPOS is a possessive repeating ket. Remember the current position,

-    and return the MATCH_KETRPOS. This makes it possible to do the repeats one

-    at a time from the outer level, thus saving stack. */

-

-    if (*ecode == OP_KETRPOS)

-      {

-      md->end_match_ptr = eptr;

-      md->end_offset_top = offset_top;

-      RRETURN(MATCH_KETRPOS);

-      }

-

     /* The normal repeating kets try the rest of the pattern or restart from

     the preceding bracket, in the appropriate order. In the second case, we can

     use tail recursion to avoid using another stack frame, unless we have an

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

index d77d8ac..6bde9ec 100644

--- a/testdata/testinput1

+++ b/testdata/testinput1

@@ -5614,4 +5614,13 @@ AbcdCBefgBhiBqz

 /[\Q]a\E]+/

     aa]]

+'\A(?:[^\"]++|\"(?:[^\"]*+|\"\")*+\")++'

+    NON QUOTED \"QUOT\"\"ED\" AFTER \"NOT MATCHED

+

+'\A(?:[^\"]++|\"(?:[^\"]++|\"\")*+\")++'

+    NON QUOTED \"QUOT\"\"ED\" AFTER \"NOT MATCHED

+

+'\A(?:[^\"]++|\"(?:[^\"]++|\"\")++\")++'

+    NON QUOTED \"QUOT\"\"ED\" AFTER \"NOT MATCHED

+

 /-- End of testinput1 --/

diff --git a/testdata/testinput8 b/testdata/testinput8

index d91013b..98a0b38 100644

--- a/testdata/testinput8

+++ b/testdata/testinput8

@@ -4801,4 +4801,10 @@

 /abcd/

     abcd\O0

+'\A(?:[^\"]++|\"(?:[^\"]*+|\"\")*+\")++'

+    NON QUOTED \"QUOT\"\"ED\" AFTER \"NOT MATCHED

+

+'\A(?:[^\"]++|\"(?:[^\"]++|\"\")*+\")++'

+    NON QUOTED \"QUOT\"\"ED\" AFTER \"NOT MATCHED

+

 /-- End of testinput8 --/

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

index 1b0b8dc..cb9592d 100644

--- a/testdata/testoutput1

+++ b/testdata/testoutput1

@@ -9208,4 +9208,16 @@ No match

     aa]]

  0: aa]]

+'\A(?:[^\"]++|\"(?:[^\"]*+|\"\")*+\")++'

+    NON QUOTED \"QUOT\"\"ED\" AFTER \"NOT MATCHED

+ 0: NON QUOTED "QUOT""ED" AFTER 

+

+'\A(?:[^\"]++|\"(?:[^\"]++|\"\")*+\")++'

+    NON QUOTED \"QUOT\"\"ED\" AFTER \"NOT MATCHED

+ 0: NON QUOTED "QUOT""ED" AFTER 

+

+'\A(?:[^\"]++|\"(?:[^\"]++|\"\")++\")++'

+    NON QUOTED \"QUOT\"\"ED\" AFTER \"NOT MATCHED

+ 0: NON QUOTED "QUOT""ED" AFTER 

+

 /-- End of testinput1 --/

diff --git a/testdata/testoutput8 b/testdata/testoutput8

index 75affbe..666b67e 100644

--- a/testdata/testoutput8

+++ b/testdata/testoutput8

@@ -8020,4 +8020,12 @@ Error -30 (invalid data in workspace for DFA restart)

     abcd\O0

 Matched, but offsets vector is too small to show all matches

+'\A(?:[^\"]++|\"(?:[^\"]*+|\"\")*+\")++'

+    NON QUOTED \"QUOT\"\"ED\" AFTER \"NOT MATCHED

+ 0: NON QUOTED "QUOT""ED" AFTER 

+

+'\A(?:[^\"]++|\"(?:[^\"]++|\"\")*+\")++'

+    NON QUOTED \"QUOT\"\"ED\" AFTER \"NOT MATCHED

+ 0: NON QUOTED "QUOT""ED" AFTER 

+

 /-- End of testinput8 --/

-- 

1.9.3