Fix *THEN in condition issue.

git-svn-id: svn://vcs.exim.org/pcre/code/trunk@699 2f5784b3-3f2a-0410-8824-cb99058d5e15

4 files changed, 56 insertions, 2 deletions

diff --git a/ChangeLog b/ChangeLog
index fde6eb0..b120f00 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -48,6 +48,9 @@ Version 8.20 12-Sep-2011
    computing a minimum subject length in the presence of *ACCEPT is difficult
    (think back references, subroutine calls), and so I have changed the code so
    that no minimum is registered for a pattern that contains *ACCEPT.
+   
+8. If (*THEN) was present in the first (true) branch of a conditional group,
+   it was not handled as intended. 
 
 
 Version 8.13 16-Aug-2011
diff --git a/pcre_exec.c b/pcre_exec.c
index 03b88bf..38447a9 100644
--- a/pcre_exec.c
+++ b/pcre_exec.c
@@ -1275,8 +1275,21 @@ for (;;)
       {
       if (op == OP_SCOND) md->match_function_type = MATCH_CBEGROUP;
       RMATCH(eptr, ecode + 1 + LINK_SIZE, offset_top, md, eptrb, RM49);
-      if (rrc == MATCH_THEN && md->start_match_ptr == ecode)
-        rrc = MATCH_NOMATCH;
+      
+      /* If the result is THEN from within the "true" branch of the condition,
+      md->start_match_ptr will point to the original OP_COND, not to the start 
+      of the branch, so we have do work to see if it matches. If THEN comes 
+      from the "false" branch, md->start_match_ptr does point to OP_ALT. */
+
+      if (rrc == MATCH_THEN)
+        {
+        if (*ecode != OP_ALT)
+          {  
+          do ecode += GET(ecode, 1); while (*ecode == OP_ALT);
+          ecode -= GET(ecode, 1);
+          } 
+        if (md->start_match_ptr == ecode) rrc = MATCH_NOMATCH;   
+        }  
       RRETURN(rrc);
       }
     else                         /* Condition false & no alternative */
diff --git a/testdata/testinput2 b/testdata/testinput2
index 453c563..739c48f 100644
--- a/testdata/testinput2
+++ b/testdata/testinput2
@@ -3733,6 +3733,21 @@ with \Y. ---/
 /^.*?(?(?=a)a|bc)/
     ba
 
+/^.*?(?(?=a)a(*THEN)b|c)/
+    ac
+
+/^.*?(?(?=a)a(*THEN)b)c/
+    ac
+
+/^.*?(a(*THEN)b)c/
+    aabc
+
+/^.*?(a(*THEN)b|z)c/
+    aabc
+
+/^.*?(z|a(*THEN)b)c/
+    aabc
+
 /-- --/
 
 /-- These studied versions are here because they are not Perl-compatible; the
diff --git a/testdata/testoutput2 b/testdata/testoutput2
index 7cae63c..e13e4df 100644
--- a/testdata/testoutput2
+++ b/testdata/testoutput2
@@ -11830,6 +11830,29 @@ No match
     ba
  0: ba
 
+/^.*?(?(?=a)a(*THEN)b|c)/
+    ac
+ 0: ac
+
+/^.*?(?(?=a)a(*THEN)b)c/
+    ac
+ 0: ac
+
+/^.*?(a(*THEN)b)c/
+    aabc
+ 0: aabc
+ 1: ab
+
+/^.*?(a(*THEN)b|z)c/
+    aabc
+ 0: aabc
+ 1: ab
+
+/^.*?(z|a(*THEN)b)c/
+    aabc
+ 0: aabc
+ 1: ab
+
 /-- --/
 
 /-- These studied versions are here because they are not Perl-compatible; the