Fix Null-dereference READ (#2382)

Signed-off-by: Mirco Miranda <mirco.miranda@systemceramics.com>
Co-authored-by: Cary Phillips <cary@ilm.com>

Author: mircomir

src/lib/OpenEXR/ImfRgbaFile.cpp

@@ -90,7 +90,11 @@ prefixFromLayerName (const string& layerName, const Header& header)
 {
     if (layerName.empty ()) return "";
 
-    if (hasMultiView (header) && multiView (header)[0] == layerName) return "";
+    if (hasMultiView (header))
+    {
+        StringVector sv = multiView (header);
+        if (!sv.empty() && sv[0] == layerName) return "";
+    }
 
     return layerName + ".";
 }

src/lib/OpenEXR/ImfTiledRgbaFile.cpp

@@ -94,7 +94,11 @@ prefixFromLayerName (const string& layerName, const Header& header)
 {
     if (layerName.empty ()) return "";
 
-    if (hasMultiView (header) && multiView (header)[0] == layerName) return "";
+    if (hasMultiView (header))
+    {
+        StringVector sv = multiView (header);
+        if (!sv.empty() && sv[0] == layerName) return "";
+    }
 
     return layerName + ".";
 }