Fix bugs when (?!) is used as a condition.

git-svn-id: svn://vcs.exim.org/pcre2/code/trunk@231 6239d852-aaf2-0410-a92c-79f79f948069

1 files changed, 6 insertions, 1 deletions

diff --git a/HACKING b/HACKING
index 1e26d01..21edebc 100644
--- a/HACKING
+++ b/HACKING
@@ -210,7 +210,8 @@ These items are all just one unit long
   OP_THEN                )
 
 OP_ASSERT_ACCEPT is used when (*ACCEPT) is encountered within an assertion.
-This ends the assertion, not the entire pattern match.
+This ends the assertion, not the entire pattern match. The assertion (?!) is 
+always optimized to OP_FAIL.
 
 
 Backtracking control verbs with optional data
@@ -528,6 +529,10 @@ immediately before the assertion. It is also possible to insert a manual
 callout at this point. Only assertion conditions may have callouts preceding
 the condition.
 
+A condition that is the negative assertion (?!) is optimized to OP_FAIL in all 
+parts of the pattern, so this is another opcode that may appear as a condition. 
+It is treated the same as OP_FALSE.
+
 
 Recursion
 ---------