From 1d44822484f3a9cf0dbe2407b7aec7c80a4afaf6 Mon Sep 17 00:00:00 2001
From: "Philip.Hazel" <Philip.Hazel@gmail.com>
Date: Tue, 9 Jun 2015 17:41:45 +0000
Subject: [PATCH] Fix empty string matching bug.

---
 ChangeLog            |  4 ++++
 src/pcre2_compile.c  |  4 ++--
 testdata/testinput2  |  2 ++
 testdata/testoutput2 | 18 ++++++++++++++++++
 4 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 544ca76..37b565d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -151,6 +151,10 @@ overflows.
 38. The table entry for \l in EBCDIC environments was incorrect, leading to its
 being treated as a literal 'l' instead of causing an error.
 
+39. If a non-capturing group containing a conditional group that could match
+an empty string was repeated, it was not identified as matching an empty string 
+itself. For example: /^(?:(?(1)x|)+)+$()/.
+
 
 Version 10.10 06-March-2015
 ---------------------------
diff --git a/src/pcre2_compile.c b/src/pcre2_compile.c
index 7acd1d5..80c2d08 100644
--- a/src/pcre2_compile.c
+++ b/src/pcre2_compile.c
@@ -1238,7 +1238,7 @@ for (code = first_significant_code(code + PRIV(OP_lengths)[*code], TRUE);
   PCRE2_SPTR ccode;
 
   c = *code;
-
+  
   /* Skip over forward assertions; the other assertions are skipped by
   first_significant_code() with a TRUE final argument. */
 
@@ -1338,7 +1338,7 @@ for (code = first_significant_code(code + PRIV(OP_lengths)[*code], TRUE);
   if (c == OP_BRA  || c == OP_BRAPOS ||
       c == OP_CBRA || c == OP_CBRAPOS ||
       c == OP_ONCE || c == OP_ONCE_NC ||
-      c == OP_COND)
+      c == OP_COND || c == OP_SCOND)
     {
     BOOL empty_branch;
     if (GET(code, 1) == 0) return TRUE;    /* Hit unclosed bracket */
diff --git a/testdata/testinput2 b/testdata/testinput2
index 70cfc06..e0e149f 100644
--- a/testdata/testinput2
+++ b/testdata/testinput2
@@ -4325,4 +4325,6 @@ a random value. /Ix
 
 /(?<=|(\,\$(?73591620449005828816)\xa8.{7}){6}\x09)/
 
+/^(?:(?(1)x|)+)+$()/B
+
 # End of testinput2 
diff --git a/testdata/testoutput2 b/testdata/testoutput2
index 7de0b8a..b628466 100644
--- a/testdata/testoutput2
+++ b/testdata/testoutput2
@@ -14452,4 +14452,22 @@ Failed: error 162 at offset 4: subpattern name expected
 /(?<=|(\,\$(?73591620449005828816)\xa8.{7}){6}\x09)/
 Failed: error 161 at offset 32: number is too big
 
+/^(?:(?(1)x|)+)+$()/B
+------------------------------------------------------------------
+        Bra
+        ^
+        SBra
+        SCond
+      1 Cond ref
+        x
+        Alt
+        KetRmax
+        KetRmax
+        $
+        CBra 1
+        Ket
+        Ket
+        End
+------------------------------------------------------------------
+
 # End of testinput2