Miscellaneous fixes (KhronosGroup#558)

* Check for correct model when loading BASIS_LZ file. Fixes KhronosGroup#557.

* Fix mismatched visibility warning in ktx2check.

* Ensure failed status is noticed after reuse lint.

* Fix license omissions in previous PR.

Author: MarkCallow

lib/basis_transcode.cpp

@@ -138,8 +138,11 @@ ktxTexture2_transcodeUastc(ktxTexture2* This,
     uint32_t* BDB = This->pDfd + 1;
     khr_df_model_e colorModel = (khr_df_model_e)KHR_DFDVAL(BDB, MODEL);
     if (colorModel != KHR_DF_MODEL_UASTC
+        // Constructor has checked color model matches BASIS_LZ.
         && This->supercompressionScheme != KTX_SS_BASIS_LZ)
-    return KTX_INVALID_OPERATION; // Not in a transcodable format.
+    {
+        return KTX_INVALID_OPERATION; // Not in a transcodable format.
+    }
 
     DECLARE_PRIVATE(priv, This);
     if (This->supercompressionScheme == KTX_SS_BASIS_LZ) {
@@ -174,7 +177,6 @@ ktxTexture2_transcodeUastc(ktxTexture2* This,
             }
         }
     } else {
-        assert(colorModel == KHR_DF_MODEL_UASTC);
         uint32_t channelId = KHR_DFDSVAL(BDB, 0, CHANNELID);
         if (channelId == KHR_DF_CHANNEL_UASTC_RGBA)
             alphaContent = eAlpha;

lib/texture2.c

@@ -709,6 +709,13 @@ ktxTexture2_constructFromStreamAndHeader(ktxTexture2* This, ktxStream* pStream,
     }
     This->isCompressed = (This->_protected->_formatSize.flags & KTX_FORMAT_SIZE_COMPRESSED_BIT);
 
+    if (This->supercompressionScheme == KTX_SS_BASIS_LZ
+        && KHR_DFDVAL(This->pDfd + 1, MODEL) != KHR_DF_MODEL_ETC1S)
+    {
+        result = KTX_FILE_DATA_ERROR;
+        goto cleanup;
+    }
+
     This->_private->_requiredLevelAlignment
                           = ktxTexture2_calcRequiredLevelAlignment(This);