- Workaround for Collada exporter in SketchUp 15.3.331 (possibly others) where it'll export the wrong "count" when exporting "lines".

- When I encounter this condition I just print a warning and use the actual number of points in the file instead of the number they give, as opposed to throwing an exception and bailing on the whole file.
	- For an example of this kind of file see https://3dwarehouse.sketchup.com/warehouse/getpubliccontent?contentId=e4587719-2609-49ed-a2f6-20b98d1215f3&fn=Kartell-GE.zip
	- Some people have complained about this on http://forums.sketchup.com/t/bug-in-lines-exported-at-collada-format/8145

code/ColladaParser.cpp

@@ -1983,7 +1983,8 @@ void ColladaParser::ReadIndexData( Mesh* pMesh)
 	}
 
 	// small sanity check
-	if (primType != Prim_TriFans && primType != Prim_TriStrips)
+	if (primType != Prim_TriFans && primType != Prim_TriStrips &&
+        primType != Prim_Lines) // this is ONLY to workaround a bug in SketchUp 15.3.331 where it writes the wrong 'count' when it writes out the 'lines'.
 		ai_assert(actualPrimitives == numPrimitives);
 
 	// only when we're done reading all <p> tags (and thus know the final vertex count) can we commit the submesh
@@ -2091,9 +2092,15 @@ size_t ColladaParser::ReadPrimitives( Mesh* pMesh, std::vector<InputChannel>& pP
 	}
 
 	// complain if the index count doesn't fit
-	if( expectedPointCount > 0 && indices.size() != expectedPointCount * numOffsets)
+    if( expectedPointCount > 0 && indices.size() != expectedPointCount * numOffsets) {
+        if (pPrimType == Prim_Lines) {
+            // HACK: We just fix this number since SketchUp 15.3.331 writes the wrong 'count' for 'lines'
+            ReportWarning( "Expected different index count in <p> element, %d instead of %d.", indices.size(), expectedPointCount * numOffsets);
+            pNumPrimitives = (indices.size() / numOffsets) / 2;
+        } else
             ThrowException( "Expected different index count in <p> element.");
-	else if( expectedPointCount == 0 && (indices.size() % numOffsets) != 0)
+
+    } else if( expectedPointCount == 0 && (indices.size() % numOffsets) != 0)
 		ThrowException( "Expected different index count in <p> element.");
 
 	// find the data for all sources
@@ -2696,6 +2703,21 @@ AI_WONT_RETURN void ColladaParser::ThrowException( const std::string& pError) co
 	throw DeadlyImportError( boost::str( boost::format( "Collada: %s - %s") % mFileName % pError));
 }
 
+void ColladaParser::ReportWarning(const char* msg,...)
+{
+    ai_assert(NULL != msg);
+    
+    va_list args;
+    va_start(args,msg);
+    
+    char szBuffer[3000];
+    const int iLen = vsprintf(szBuffer,msg,args);
+    ai_assert(iLen > 0);
+    
+    va_end(args);
+    DefaultLogger::get()->warn("Validation warning: " + std::string(szBuffer,iLen));
+}
+
 // ------------------------------------------------------------------------------------------------
 // Skips all data until the end node of the current element
 void ColladaParser::SkipElement()

code/ColladaParser.h

@@ -213,6 +213,7 @@ protected:
 protected:
 	/** Aborts the file reading with an exception */
 	AI_WONT_RETURN void ThrowException( const std::string& pError) const AI_WONT_RETURN_SUFFIX;
+    void ReportWarning(const char* msg,...);
 
 	/** Skips all data until the end node of the current element */
 	void SkipElement();