From 7003255c0e6d9e80295d04ee416f25db38fa7b0d Mon Sep 17 00:00:00 2001
From: Artem Pavlenko <artem@mapnik.org>
Date: Tue, 5 Nov 2019 09:50:51 +0000
Subject: [PATCH] avoid negative indicies access to `parenStack` - thanks
 @talaj! (ref #4096)

---
 src/text/scrptrun.cpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/text/scrptrun.cpp b/src/text/scrptrun.cpp
index 071b7b239..1bdf797b7 100644
--- a/src/text/scrptrun.cpp
+++ b/src/text/scrptrun.cpp
@@ -162,6 +162,7 @@ UBool ScriptRun::next()
             if ((pairIndex & 1) == 0) {
                 ++parenSP;
                 parenStack.emplace_back(pairIndex, scriptCode);
+                startSP = parenSP;
             } else if (parenSP >= 0) {
                 int32_t pi = pairIndex & ~1;