From 945e309564e500dc32642fe3e9fd51a812d5baa7 Mon Sep 17 00:00:00 2001
From: ichesnok <ichesnok@opencascade.com>
Date: Mon, 27 Mar 2023 09:37:44 +0100
Subject: [PATCH] 0030066: Data Exchange - Fail to load VRML from ArcGIS

Fixed VrmlData_Scene::readHeader method
---
 src/VrmlData/VrmlData_Scene.cxx | 21 ++++++++++++++++-----
 tests/bugs/stlvrml/bug30066     |  6 ++++++
 2 files changed, 22 insertions(+), 5 deletions(-)
 create mode 100644 tests/bugs/stlvrml/bug30066

diff --git a/src/VrmlData/VrmlData_Scene.cxx b/src/VrmlData/VrmlData_Scene.cxx
index 1c851aab42..a263c23bbd 100644
--- a/src/VrmlData/VrmlData_Scene.cxx
+++ b/src/VrmlData/VrmlData_Scene.cxx
@@ -314,12 +314,23 @@ VrmlData_ErrorStatus VrmlData_Scene::ReadLine (VrmlData_InBuffer& theBuffer)
 
 VrmlData_ErrorStatus VrmlData_Scene::readHeader (VrmlData_InBuffer& theBuffer)
 {
-  VrmlData_ErrorStatus aStat = readLine (theBuffer);
-  if (aStat == VrmlData_StatusOK &&
-      !VRMLDATA_LCOMPARE(theBuffer.LinePtr, "#VRML V2.0"))
-    aStat = VrmlData_NotVrmlFile;
-  else 
+  VrmlData_ErrorStatus aStat = readLine(theBuffer);
+  if (aStat != VrmlData_StatusOK)
+  {
+    return VrmlData_NotVrmlFile;
+  }
+  TCollection_AsciiString aHeader(theBuffer.LinePtr);
+  // The max possible header size is 25 (with spaces)
+  // 4 (max BOM size) + 11 (search string) + 9 (max size for encoding)
+  if (aHeader.Length() <= 25 &&
+      aHeader.Search("#VRML V2.0") != -1)
+  {
     aStat = readLine(theBuffer);
+  }
+  else
+  {
+    aStat = VrmlData_NotVrmlFile;
+  }
   return aStat;
 }
 
diff --git a/tests/bugs/stlvrml/bug30066 b/tests/bugs/stlvrml/bug30066
new file mode 100644
index 0000000000..95aac17ed3
--- /dev/null
+++ b/tests/bugs/stlvrml/bug30066
@@ -0,0 +1,6 @@
+puts "========"
+puts "0030066: Data Exchange - Fail to load VRML from ArcGIS"
+puts "========"
+puts ""
+
+loadvrml sh [locate_data_file bug30066.wrl]
\ No newline at end of file