Fix study bug with single-branch conditions, including (DEFINE).

git-svn-id: svn://vcs.exim.org/pcre/code/trunk@471 2f5784b3-3f2a-0410-8824-cb99058d5e15

5 files changed, 57 insertions, 4 deletions

diff --git a/ChangeLog b/ChangeLog
index 40600b8..749a674 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,6 +1,15 @@
 ChangeLog for PCRE
 ------------------
 
+Version 8.01 11-Dec-09
+----------------------
+
+1.  If a pattern contained a conditional subpattern with only one branch (in
+    particular, this includes all (DEFINE) patterns), a call to pcre_study() 
+    computed the wrong minimum data length (which is of course zero for such 
+    subpatterns).
+
+
 Version 8.00 19-Oct-09
 ----------------------
 
diff --git a/configure.ac b/configure.ac
index 612810b..fc96ec4 100644
--- a/configure.ac
+++ b/configure.ac
@@ -7,9 +7,9 @@ dnl be defined as -RC2, for example. For real releases, it should be defined
 dnl empty.
 
 m4_define(pcre_major, [8])
-m4_define(pcre_minor, [00])
+m4_define(pcre_minor, [01])
 m4_define(pcre_prerelease, [])
-m4_define(pcre_date, [2009-10-19])
+m4_define(pcre_date, [2009-12-11])
 
 # Libtool shared library interface versions (current:revision:age)
 m4_define(libpcre_version, [0:1:0])
diff --git a/pcre_study.c b/pcre_study.c
index 2462e3b..957a1fe 100644
--- a/pcre_study.c
+++ b/pcre_study.c
@@ -96,13 +96,28 @@ for (;;)
 
   switch (op)
     {
+    case OP_COND:
+    case OP_SCOND:
+
+    /* If there is only one branch in a condition, the implied branch has zero
+    length, so we don't add anything. This covers the DEFINE "condition"
+    automatically. */
+
+    cs = cc + GET(cc, 1);
+    if (*cs != OP_ALT)
+      {
+      cc = cs + 1 + LINK_SIZE;
+      break;
+      }
+
+    /* Otherwise we can fall through and treat it the same as any other
+    subpattern. */
+
     case OP_CBRA:
     case OP_SCBRA:
     case OP_BRA:
     case OP_SBRA:
     case OP_ONCE:
-    case OP_COND:
-    case OP_SCOND:
     d = find_minlength(cc, startcode, options);
     if (d < 0) return d;
     branchlength += d;
diff --git a/testdata/testinput2 b/testdata/testinput2
index 3319bb7..c49b94f 100644
--- a/testdata/testinput2
+++ b/testdata/testinput2
@@ -3169,4 +3169,10 @@ a random value. /Ix
 /(\3)(\1)(a)/SI
     cat
 
+/i(?(DEFINE)(?<s>a))/SI
+    i
+    
+/()i(?(1)a)/SI 
+    ia
+
 /-- End of testinput2 --/
diff --git a/testdata/testoutput2 b/testdata/testoutput2
index 30ea63b..be968da 100644
--- a/testdata/testoutput2
+++ b/testdata/testoutput2
@@ -10463,4 +10463,27 @@ No set of starting bytes
     cat
 No match
 
+/i(?(DEFINE)(?<s>a))/SI
+Capturing subpattern count = 1
+Named capturing subpatterns:
+  s   1
+No options
+First char = 'i'
+No need char
+Subject length lower bound = 1
+No set of starting bytes
+    i
+ 0: i
+    
+/()i(?(1)a)/SI 
+Capturing subpattern count = 1
+No options
+No first char
+Need char = 'i'
+Subject length lower bound = 1
+Starting byte set: i 
+    ia
+ 0: ia
+ 1: 
+
 /-- End of testinput2 --/