From d291e55bdb4dce840f082a7c884f8b3b79950126 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Martin=20T=C5=AFma?= <tumic@cbox.cz>
Date: Thu, 22 Oct 2020 20:32:12 +0200
Subject: [PATCH] Fixed label pointer parsing

---
 src/map/IMG/bitstream.cpp | 16 ++++++++++++++++
 src/map/IMG/bitstream.h   |  2 ++
 src/map/IMG/netfile.cpp   | 19 +++++++++----------
 3 files changed, 27 insertions(+), 10 deletions(-)

diff --git a/src/map/IMG/bitstream.cpp b/src/map/IMG/bitstream.cpp
index 3836155b..8dd7f53d 100644
--- a/src/map/IMG/bitstream.cpp
+++ b/src/map/IMG/bitstream.cpp
@@ -12,6 +12,22 @@ bool BitStream1::flush()
 	return true;
 }
 
+bool BitStream1::readUInt24(quint32 &val)
+{
+	quint8 b;
+
+	val = 0;
+
+	for (int i = 0; i < 3; i++) {
+		if (!read(8, b))
+			return false;
+		val |= (b << (i * 8));
+	}
+
+	return true;
+}
+
+
 bool BitStream4F::flush()
 {
 	if (_length && !_file.seek(_hdl, _file.pos(_hdl) + _length))
diff --git a/src/map/IMG/bitstream.h b/src/map/IMG/bitstream.h
index bf3103f4..d307c71c 100644
--- a/src/map/IMG/bitstream.h
+++ b/src/map/IMG/bitstream.h
@@ -12,6 +12,8 @@ public:
 	bool flush();
 	quint64 bitsAvailable() const {return (quint64)_length * 8 + _remaining;}
 
+	bool readUInt24(quint32 &val);
+
 private:
 	const SubFile &_file;
 	SubFile::Handle &_hdl;
diff --git a/src/map/IMG/netfile.cpp b/src/map/IMG/netfile.cpp
index 3ae72899..6388abf6 100644
--- a/src/map/IMG/netfile.cpp
+++ b/src/map/IMG/netfile.cpp
@@ -352,21 +352,19 @@ bool NETFile::linkLabel(Handle &hdl, quint32 offset, quint32 size, LBLFile *lbl,
 		return false;
 	BitStream1 bs(*this, hdl, size);
 
-	quint32 flags, b, labelPtr = 0;
+	quint32 flags, labelPtr;
 	if (!bs.read(8, flags))
 		return false;
-	for (int i = 0; i < 3; i++) {
-		if (!bs.read(8, b))
-			return false;
-		labelPtr |= (b << (i * 8));
-	}
+	if (!(flags & 1))
+		return true;
 
-	if (lbl && (labelPtr & 0x3FFFFF)) {
+	if (!bs.readUInt24(labelPtr))
+		return false;
+	if (labelPtr & 0x3FFFFF) {
 		if (labelPtr & 0x400000) {
 			quint32 lblOff;
 			if (lblOffset(hdl, labelPtr & 0x3FFFFF, lblOff) && lblOff)
 				label = lbl->label(lblHdl, lblOff);
-
 		} else
 			label = lbl->label(lblHdl, labelPtr & 0x3FFFFF);
 	}
@@ -489,8 +487,9 @@ bool NETFile::link(const SubDiv *subdiv, quint32 shift, Handle &hdl,
 			return false;
 	}
 
-	linkLabel(hdl, linkOffset, _linksSize - (linkOffset - _linksOffset), lbl,
-	  lblHdl, poly.label);
+	if (lbl)
+		linkLabel(hdl, linkOffset, _linksSize - (linkOffset - _linksOffset),
+		  lbl, lblHdl, poly.label);
 
 	lines->append(poly);