From 7abc4de8303e8908eeb96714dac53ae10ff465e3 Mon Sep 17 00:00:00 2001
From: ph10 <ph10@2f5784b3-3f2a-0410-8824-cb99058d5e15>
Date: Sun, 2 Sep 2018 17:05:38 +0000
Subject: [PATCH] Fix anchoring bug in conditional subexpression.
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git-svn-id: svn://vcs.exim.org/pcre/code/trunk@1739 2f5784b3-3f2a-0410-8824-cb99058d5e15
Petr Písař: Ported to 8.42
---
 pcre_compile.c       | 12 ++++++++++--
 testdata/testinput2  |  3 +++
 testdata/testoutput2 |  4 ++++

 Version 8.42 20-March-2018
 --------------------------
diff --git a/pcre_compile.c b/pcre_compile.c
index 3991d6c..6141fb3 100644
--- a/pcre_compile.c
+++ b/pcre_compile.c
@@ -8682,10 +8682,18 @@ do {
      if (!is_anchored(scode, new_map, cd, atomcount)) return FALSE;
      }
 
-   /* Positive forward assertions and conditions */
+   /* Positive forward assertion */
 
-   else if (op == OP_ASSERT || op == OP_COND)
+   else if (op == OP_ASSERT)
+     {
+     if (!is_anchored(scode, bracket_map, cd, atomcount)) return FALSE;
+     }
+
+   /* Condition; not anchored if no second branch */
+
+   else if (op == OP_COND)
      {
+     if (scode[GET(scode,1)] != OP_ALT) return FALSE;
      if (!is_anchored(scode, bracket_map, cd, atomcount)) return FALSE;
      }
 
diff --git a/testdata/testinput2 b/testdata/testinput2
index 8ba4dc4..3528de1 100644
--- a/testdata/testinput2
+++ b/testdata/testinput2
@@ -4257,4 +4257,7 @@ backtracking verbs. --/
     ab
     aaab 
 
+/(?(?=^))b/
+    abc
+
 /-- End of testinput2 --/
diff --git a/testdata/testoutput2 b/testdata/testoutput2
index 61ed8d9..4ccda27 100644
--- a/testdata/testoutput2
+++ b/testdata/testoutput2
@@ -14721,4 +14721,8 @@ No need char
  0: ab
  1: a
 
+/(?(?=^))b/
+    abc
+ 0: b
+
 /-- End of testinput2 --/
-- 
2.14.4