some XSLT bugfixes

data/schema/upgrade_0.3.0.xsl

@@ -43,13 +43,21 @@
 		</lookAt>
 	</xsl:template>
 
+	<xsl:template match="shape">
+		<xsl:copy>
+			<xsl:apply-templates select="@*|node()"/>
+
 			<!-- The vertical component of OBJ texture coordinates is now
 			     flipped, which seems to be the standard behavior. Undo 
 				 this change for consistency in old scenes. -->
-	<xsl:template match="shape[@type='obj']">
+			<xsl:if test="@type='obj'">
-		<xsl:copy>
-			<xsl:apply-templates select="@*|node()"/>
 				<boolean name="flipTexCoords" value="false"/>
+			</xsl:if>
+
+			<!-- Apply a diffuse material to shapes that don't have any media or BSDFs -->
+			<xsl:if test="not(bsdf) and not(ref) and not(medium) and not(subsurface)">
+				<bsdf type="diffuse"/>
+			</xsl:if>
 		</xsl:copy>
 	</xsl:template>
 
@@ -150,14 +158,6 @@
 		</xsl:choose>
 	</xsl:template>
 
-	<!-- Apply a diffuse material to shapes that don't have any media or BSDFs -->
-	<xsl:template match="shape[not(bsdf) and not(ref) and not(medium)]">
-		<xsl:copy>
-			<xsl:apply-templates select="@*|node()"/>
-			<bsdf type="diffuse"/>
-		</xsl:copy>
-	</xsl:template>
-
 	<!-- Update the parameters of the sphere plugin -->
 	<xsl:template match="shape[@type='sphere']/boolean[@name='inverted']/@name">
 		<xsl:attribute name="name">flipNormals</xsl:attribute>