From 6f516ffef41280fbd9fd451fc7eab0c9ce98efad Mon Sep 17 00:00:00 2001
From: ph10 <ph10@6239d852-aaf2-0410-a92c-79f79f948069>
Date: Sun, 26 Jan 2020 15:31:27 +0000
Subject: [PATCH] Fix bug in processing (?(DEFINE)...) within lookbehind
 assertions.
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git-svn-id: svn://vcs.exim.org/pcre2/code/trunk@1212 6239d852-aaf2-0410-a92c-79f79f948069
Petr Písař: Ported to 10.34.

Signed-off-by: Petr Písař <ppisar@redhat.com>
---
 src/pcre2_compile.c  | 20 ++++++++++++++------
 testdata/testinput1  | 13 +++++++++++++
 testdata/testinput2  |  4 ++++
 testdata/testoutput1 | 17 +++++++++++++++++
 testdata/testoutput2 |  5 +++++
 5 files changed, 53 insertions(+), 6 deletions(-)

diff --git a/src/pcre2_compile.c b/src/pcre2_compile.c
index f2e6b6b..628503c 100644
--- a/src/pcre2_compile.c
+++ b/src/pcre2_compile.c
@@ -8836,9 +8836,10 @@ memset(slot + IMM2_SIZE + length, 0,
 
 /* This function is called to skip parts of the parsed pattern when finding the
 length of a lookbehind branch. It is called after (*ACCEPT) and (*FAIL) to find
-the end of the branch, it is called to skip over an internal lookaround, and it
-is also called to skip to the end of a class, during which it will never
-encounter nested groups (but there's no need to have special code for that).
+the end of the branch, it is called to skip over an internal lookaround or
+(DEFINE) group, and it is also called to skip to the end of a class, during
+which it will never encounter nested groups (but there's no need to have
+special code for that).
 
 When called to find the end of a branch or group, pptr must point to the first
 meta code inside the branch, not the branch-starting code. In other cases it
@@ -9316,14 +9317,21 @@ for (;; pptr++)
     itemlength = grouplength;
     break;
 
-    /* Check nested groups - advance past the initial data for each type and
-    then seek a fixed length with get_grouplength(). */
+    /* A (DEFINE) group is never obeyed inline and so it does not contribute to
+    the length of this branch. Skip from the following item to the next
+    unpaired ket. */
+
+    case META_COND_DEFINE:
+    pptr = parsed_skip(pptr + 1, PSKIP_KET);
+    break;
+
+    /* Check other nested groups - advance past the initial data for each type
+    and then seek a fixed length with get_grouplength(). */
 
     case META_COND_NAME:
     case META_COND_NUMBER:
     case META_COND_RNAME:
     case META_COND_RNUMBER:
-    case META_COND_DEFINE:
     pptr += 2 + SIZEOFFSET;
     goto CHECK_GROUP;
 
diff --git a/testdata/testinput1 b/testdata/testinput1
index f5159d6..959d4b8 100644
--- a/testdata/testinput1
+++ b/testdata/testinput1
@@ -6386,4 +6386,17 @@ ef) x/x,mark
 /^(?<A>a)(?(<A>)b)((?<=b).*)$/
     abc
 
+"(?<=X(?(DEFINE)(A)))X(*F)"
+\= Expect no match
+    AXYZ
+
+"(?<=X(?(DEFINE)(A)))."
+    AXYZ
+
+"(?<=X(?(DEFINE)(.*))Y)."
+    AXYZ
+
+"(?<=X(?(DEFINE)(Y))(?1))."
+    AXYZ
+
 # End of testinput1 
diff --git a/testdata/testinput2 b/testdata/testinput2
index 655e519..7f70860 100644
--- a/testdata/testinput2
+++ b/testdata/testinput2
@@ -5772,4 +5772,8 @@ a)"xI
 /(a)?a/I
     manm
 
+# Expect non-fixed-length error
+
+"(?<=X(?(DEFINE)(.*))(?1))."
+
 # End of testinput2
diff --git a/testdata/testoutput1 b/testdata/testoutput1
index ad2175b..dfb6366 100644
--- a/testdata/testoutput1
+++ b/testdata/testoutput1
@@ -10112,4 +10112,21 @@ No match
  1: a
  2: c
 
+"(?<=X(?(DEFINE)(A)))X(*F)"
+\= Expect no match
+    AXYZ
+No match
+
+"(?<=X(?(DEFINE)(A)))."
+    AXYZ
+ 0: Y
+
+"(?<=X(?(DEFINE)(.*))Y)."
+    AXYZ
+ 0: Z
+
+"(?<=X(?(DEFINE)(Y))(?1))."
+    AXYZ
+ 0: Z
+
 # End of testinput1 
diff --git a/testdata/testoutput2 b/testdata/testoutput2
index c733c12..69d1a7b 100644
--- a/testdata/testoutput2
+++ b/testdata/testoutput2
@@ -17435,6 +17435,11 @@ Subject length lower bound = 1
     manm
  0: a
 
+# Expect non-fixed-length error
+
+"(?<=X(?(DEFINE)(.*))(?1))."
+Failed: error 125 at offset 0: lookbehind assertion is not fixed length
+
 # End of testinput2
 Error -70: PCRE2_ERROR_BADDATA (unknown error number)
 Error -62: bad serialized data
-- 
2.21.1