Fix conditional group backreference bug.

ChangeLog

@@ -1,6 +1,22 @@
 Change Log for PCRE2
 --------------------
 
+Version 10.10 13-January-2015
+-----------------------------
+
+1. When a pattern is compiled, it remembers the highest back reference so that 
+when matching, if the ovector is too small, extra memory can be obtained to 
+use instead. A conditional subpattern whose condition is a check on a capture
+having happened, such as, for example in the pattern /^(?:(a)|b)(?(1)A|B)/, is
+another kind of back reference, but it was not setting the highest
+backreference number. This mattered only if pcre2_match() was called with an
+ovector that was too small to hold the capture, and there was no other kind of
+back reference (a situation which is probably quite rare). The effect of the
+bug was that the condition was always treated as FALSE when the capture could
+not be consulted, leading to a incorrect behaviour by pcre2_match(). This bug
+has been fixed.
+
+
 Version 10.00 05-January-2015 
 -----------------------------
 

configure.ac

@@ -9,9 +9,9 @@ dnl The PCRE2_PRERELEASE feature is for identifying release candidates. It might
 dnl be defined as -RC2, for example. For real releases, it should be empty.
 
 m4_define(pcre2_major, [10])
-m4_define(pcre2_minor, [00])
+m4_define(pcre2_minor, [10])
-m4_define(pcre2_prerelease, [])
+m4_define(pcre2_prerelease, [-RC1])
-m4_define(pcre2_date, [2014-01-05])
+m4_define(pcre2_date, [2014-01-13])
 
 # NOTE: The CMakeLists.txt file searches for the above variables in the first
 # 50 lines of this file. Please update that if the variables above are moved.

doc/pcre2api.3

@@ -1,4 +1,4 @@
-.TH PCRE2API 3 "02 January 2015" "PCRE2 10.00"
+.TH PCRE2API 3 "13 January 2015" "PCRE2 10.10"
 .SH NAME
 PCRE2 - Perl-compatible regular expressions (revised API)
 .sp
@@ -1474,8 +1474,12 @@ options returned for PCRE2_INFO_ALLOPTIONS.
   PCRE2_INFO_BACKREFMAX
 .sp
 Return the number of the highest back reference in the pattern. The third
-argument should point to an \fBuint32_t\fP variable. Zero is returned if there
+argument should point to an \fBuint32_t\fP variable. Named subpatterns acquire
-are no back references.
+numbers as well as names, and these count towards the highest back reference.
+Back references such as \e4 or \eg{12} match the captured characters of the
+given group, but in addition, the check that a capturing group is set in a
+conditional subpattern such as (?(3)a|b) is also a back reference. Zero is
+returned if there are no back references.
 .sp
   PCRE2_INFO_BSR
 .sp
@@ -2849,6 +2853,6 @@ Cambridge, England.
 .rs
 .sp
 .nf
-Last updated: 02 January 2015
+Last updated: 13 January 2015
 Copyright (c) 1997-2015 University of Cambridge.
 .fi

src/pcre2_compile.c

@@ -5336,6 +5336,7 @@ for (;; ptr++)
             goto FAILED;
             }
           PUT2(code, 2+LINK_SIZE, recno);
+          if (recno > cb->top_backref) cb->top_backref = recno;
           break;
           }
 
@@ -5355,15 +5356,18 @@ for (;; ptr++)
 
         if (i < cb->names_found)
           {
-          int offset = i++;
+          int offset = i;            /* Offset of first name found */
-          int count = 1;
+          int count = 0;
-          recno = GET2(slot, 0);   /* Number from first found */
+           
-          for (; i < cb->names_found; i++)
+          for (;;)
             {
+            recno = GET2(slot, 0);   /* Number for last found */
+            if (recno > cb->top_backref) cb->top_backref = recno;
+            count++;
+            if (++i >= cb->names_found) break; 
             slot += cb->name_entry_size;
             if (PRIV(strncmp)(name, slot+IMM2_SIZE, namelen) != 0 ||
               (slot+IMM2_SIZE)[namelen] != 0) break;
-            count++;
             }
 
           if (count > 1)

testdata/testinput2

@@ -4116,4 +4116,22 @@ a random value. /Ix
 
 /(*NO_DOTSTAR_ANCHOR)(?s).*\d/info
 
+'^(?:(a)|b)(?(1)A|B)'
+    aA123\=ovector=1
+    aA123\=ovector=2
+
+'^(?:(?<AA>a)|b)(?(<AA>)A|B)'
+    aA123\=ovector=1
+    aA123\=ovector=2
+
+'^(?<AA>)(?:(?<AA>a)|b)(?(<AA>)A|B)'dupnames
+    aA123\=ovector=1
+    aA123\=ovector=2
+    aA123\=ovector=3
+
+'^(?:(?<AA>X)|)(?:(?<AA>a)|b)\k{AA}'dupnames
+    aa123\=ovector=1
+    aa123\=ovector=2
+    aa123\=ovector=3
+
 # End of testinput2 

testdata/testoutput2

@@ -1535,28 +1535,33 @@ Subject length lower bound = 3
 
 /a(?(1)b)(.)/I
 Capturing subpattern count = 1
+Max back reference = 1
 First code unit = 'a'
 Subject length lower bound = 2
 
 /a(?(1)bag|big)(.)/I
 Capturing subpattern count = 1
+Max back reference = 1
 First code unit = 'a'
 Last code unit = 'g'
 Subject length lower bound = 5
 
 /a(?(1)bag|big)*(.)/I
 Capturing subpattern count = 1
+Max back reference = 1
 First code unit = 'a'
 Subject length lower bound = 2
 
 /a(?(1)bag|big)+(.)/I
 Capturing subpattern count = 1
+Max back reference = 1
 First code unit = 'a'
 Last code unit = 'g'
 Subject length lower bound = 5
 
 /a(?(1)b..|b..)(.)/I
 Capturing subpattern count = 1
+Max back reference = 1
 First code unit = 'a'
 Last code unit = 'b'
 Subject length lower bound = 5
@@ -3345,21 +3350,25 @@ Subject length lower bound = 1
 
 /(?(1)ab|ac)(.)/I
 Capturing subpattern count = 1
+Max back reference = 1
 First code unit = 'a'
 Subject length lower bound = 3
 
 /(?(1)abz|acz)(.)/I
 Capturing subpattern count = 1
+Max back reference = 1
 First code unit = 'a'
 Last code unit = 'z'
 Subject length lower bound = 4
 
 /(?(1)abz)(.)/I
 Capturing subpattern count = 1
+Max back reference = 1
 Subject length lower bound = 1
 
 /(?(1)abz)(1)23/I
 Capturing subpattern count = 1
+Max back reference = 1
 Last code unit = '3'
 Subject length lower bound = 3
 
@@ -5923,6 +5932,7 @@ Subject length lower bound = 6
 
 /^(?P<A>a)?(?(A)a|b)/I
 Capturing subpattern count = 1
+Max back reference = 1
 Named capturing subpatterns:
   A   1
 Compile options: <none>
@@ -5940,6 +5950,7 @@ No match
 
 /(?:(?(ZZ)a|b)(?P<ZZ>X))+/I
 Capturing subpattern count = 1
+Max back reference = 1
 Named capturing subpatterns:
   ZZ   1
 Last code unit = 'X'
@@ -5956,6 +5967,7 @@ Failed: error 115 at offset 9: reference to non-existent subpattern
 
 /(?:(?(ZZ)a|b)(?(ZZ)a|b)(?P<ZZ>X))+/I
 Capturing subpattern count = 1
+Max back reference = 1
 Named capturing subpatterns:
   ZZ   1
 Last code unit = 'X'
@@ -5966,6 +5978,7 @@ Subject length lower bound = 3
 
 /(?:(?(ZZ)a|\(b\))\\(?P<ZZ>X))+/I
 Capturing subpattern count = 1
+Max back reference = 1
 Named capturing subpatterns:
   ZZ   1
 Last code unit = 'X'
@@ -9713,6 +9726,7 @@ Subject length lower bound = 9
   (?(1)|.)                    # check that there was an empty component
   /Iix
 Capturing subpattern count = 1
+Max back reference = 1
 Compile options: caseless extended
 Overall options: anchored caseless extended
 Last code unit = ':'
@@ -9740,6 +9754,7 @@ Failed: error 165 at offset 15: different names for subpatterns of the same numb
     b(?<quote> (?<apostrophe>')|(?<realquote>")) ) 
     (?('quote')[a-z]+|[0-9]+)/Ix,dupnames
 Capturing subpattern count = 6
+Max back reference = 4
 Named capturing subpatterns:
   apostrophe   2
   apostrophe   5
@@ -9802,6 +9817,7 @@ No match
         End
 ------------------------------------------------------------------
 Capturing subpattern count = 4
+Max back reference = 4
 Named capturing subpatterns:
   D   4
   D   1
@@ -9849,6 +9865,7 @@ No match
         End
 ------------------------------------------------------------------
 Capturing subpattern count = 4
+Max back reference = 4
 Named capturing subpatterns:
   A   1
   A   4
@@ -9964,6 +9981,7 @@ Subject length lower bound = 1
     
 /()i(?(1)a)/I
 Capturing subpattern count = 1
+Max back reference = 1
 First code unit = 'i'
 Subject length lower bound = 1
     ia
@@ -13540,6 +13558,7 @@ No match
 
 /(?:(?<VERSION>abc)|xyz)(?(VERSION)yes|no)/I
 Capturing subpattern count = 1
+Max back reference = 1
 Named capturing subpatterns:
   VERSION   1
 Starting code units: a x 
@@ -13832,4 +13851,46 @@ Compile options: <none>
 Overall options: dotall no_dotstar_anchor
 Subject length lower bound = 1
 
+'^(?:(a)|b)(?(1)A|B)'
+    aA123\=ovector=1
+Matched, but too many substrings
+ 0: aA
+    aA123\=ovector=2
+ 0: aA
+ 1: a
+
+'^(?:(?<AA>a)|b)(?(<AA>)A|B)'
+    aA123\=ovector=1
+Matched, but too many substrings
+ 0: aA
+    aA123\=ovector=2
+ 0: aA
+ 1: a
+
+'^(?<AA>)(?:(?<AA>a)|b)(?(<AA>)A|B)'dupnames
+    aA123\=ovector=1
+Matched, but too many substrings
+ 0: aA
+    aA123\=ovector=2
+Matched, but too many substrings
+ 0: aA
+ 1: 
+    aA123\=ovector=3
+ 0: aA
+ 1: 
+ 2: a
+
+'^(?:(?<AA>X)|)(?:(?<AA>a)|b)\k{AA}'dupnames
+    aa123\=ovector=1
+Matched, but too many substrings
+ 0: aa
+    aa123\=ovector=2
+Matched, but too many substrings
+ 0: aa
+ 1: <unset>
+    aa123\=ovector=3
+ 0: aa
+ 1: <unset>
+ 2: a
+
 # End of testinput2