Fix non-diagnosis of missing assertion after (?(?< not followed by ! or =.

git-svn-id: svn://vcs.exim.org/pcre/code/trunk@1539 2f5784b3-3f2a-0410-8824-cb99058d5e15

4 files changed, 26 insertions, 14 deletions

diff --git a/ChangeLog b/ChangeLog
index aa60599..aa51d88 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -131,6 +131,11 @@ Version 8.37 xx-xxx-2015
     between a subroutine call and its quantifier was incorrectly compiled,
     leading to buffer overflow or other errors. This bug was discovered by the
     LLVM fuzzer.
+    
+33. The illegal pattern /(?(?<E>.*!.*)?)/ was not being diagnosed as missing an
+    assertion after (?(. The code was failing to check the character after
+    (?(?< for the ! or = that would indicate a lookbehind assertion. This bug
+    was discovered by the LLVM fuzzer.
 
 
 Version 8.36 26-September-2014
diff --git a/pcre_compile.c b/pcre_compile.c
index 810df84..94e78db 100644
--- a/pcre_compile.c
+++ b/pcre_compile.c
@@ -2497,7 +2497,7 @@ for (code = first_significant_code(code + PRIV(OP_lengths)[*code], TRUE);
       empty_branch = FALSE;
       do
         {
-        if (!empty_branch && could_be_empty_branch(code, endcode, utf, cd, 
+        if (!empty_branch && could_be_empty_branch(code, endcode, utf, cd,
           recurses)) empty_branch = TRUE;
         code += GET(code, 1);
         }
@@ -6476,18 +6476,18 @@ for (;; ptr++)
 
     /* First deal with comments. Putting this code right at the start ensures
     that comments have no bad side effects. */
-                                                                            
-    if (ptr[0] == CHAR_QUESTION_MARK && ptr[1] == CHAR_NUMBER_SIGN)       
-      {                                                       
-      ptr += 2;                
+
+    if (ptr[0] == CHAR_QUESTION_MARK && ptr[1] == CHAR_NUMBER_SIGN)
+      {
+      ptr += 2;
       while (*ptr != CHAR_NULL && *ptr != CHAR_RIGHT_PARENTHESIS) ptr++;
-      if (*ptr == CHAR_NULL)                                     
-        {                                                                 
-        *errorcodeptr = ERR18;                                          
-        goto FAILED;                                               
-        }                                                           
-      continue;                                                         
-      }                        
+      if (*ptr == CHAR_NULL)
+        {
+        *errorcodeptr = ERR18;
+        goto FAILED;
+        }
+      continue;
+      }
 
     /* Now deal with various "verbs" that can be introduced by '*'. */
 
@@ -6679,7 +6679,9 @@ for (;; ptr++)
         if (tempptr[1] == CHAR_QUESTION_MARK &&
               (tempptr[2] == CHAR_EQUALS_SIGN ||
                tempptr[2] == CHAR_EXCLAMATION_MARK ||
-               tempptr[2] == CHAR_LESS_THAN_SIGN))
+                 (tempptr[2] == CHAR_LESS_THAN_SIGN &&
+                   (tempptr[3] == CHAR_EQUALS_SIGN ||
+                    tempptr[3] == CHAR_EXCLAMATION_MARK))))
           {
           cd->iscondassert = TRUE;
           break;
diff --git a/testdata/testinput2 b/testdata/testinput2
index 40593e3..0e29c7a 100644
--- a/testdata/testinput2
+++ b/testdata/testinput2
@@ -4136,4 +4136,6 @@ backtracking verbs. --/
 
 "((?2)+)((?1))"
 
+"(?(?<E>.*!.*)?)"
+
 /-- End of testinput2 --/
diff --git a/testdata/testoutput2 b/testdata/testoutput2
index 28937c8..f3b2dc4 100644
--- a/testdata/testoutput2
+++ b/testdata/testoutput2
@@ -561,7 +561,7 @@ Failed: assertion expected after (?( at offset 3
 Failed: reference to non-existent subpattern at offset 7
 
 /(?(?<ab))/
-Failed: syntax error in subpattern name (missing terminator) at offset 7
+Failed: assertion expected after (?( at offset 3
 
 /((?s)blah)\s+\1/I
 Capturing subpattern count = 1
@@ -14345,4 +14345,7 @@ No match
 
 "((?2)+)((?1))"
 
+"(?(?<E>.*!.*)?)"
+Failed: assertion expected after (?( at offset 3
+
 /-- End of testinput2 --/