From 56830948e35b1cd124e83db016fccce75671752f Mon Sep 17 00:00:00 2001
From: Arne Welzel <arne.welzel@corelight.com>
Date: Wed, 15 Nov 2023 19:41:27 +0100
Subject: [PATCH] RE_Match_State: Do not reset current_pos for every Match()
 call

This seems like a bug: If one feeds one byte at a time, current_pos
is being reset for every byte, possibly reporting the wrong offsets
in the accepted_matches map.
---
 src/RE.cc | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/RE.cc b/src/RE.cc
index db5dad6d07..67144e9bd4 100644
--- a/src/RE.cc
+++ b/src/RE.cc
@@ -268,6 +268,7 @@ bool RE_Match_State::Match(const u_char* bv, int n, bool bol, bool eol, bool cle
 
         // Initialize state and copy the accepting states of the start
         // state into the acceptance set.
+        current_pos = 0;
         current_state = dfa->StartState();
 
         const AcceptingSet* ac = current_state->Accept();
@@ -276,13 +277,14 @@ bool RE_Match_State::Match(const u_char* bv, int n, bool bol, bool eol, bool cle
             AddMatches(*ac, 0);
     }
 
-    else if ( clear )
+    else if ( clear ) {
+        current_pos = 0;
         current_state = dfa->StartState();
+    }
 
     if ( ! current_state )
         return false;
 
-    current_pos = 0;
 
     size_t old_matches = accepted_matches.size();