#658: avoid crash when Textures.high is missing

Don't resolve the empty file name, which would result in the fgdata
directory path (instead of a path to a file). Eventually this resulted in
a segfault, partly due to a bug in "osgDB::readImageFile", which reports
"success" when given a directory (instead of a file) path, though it
doesn't return a valid image object.

CMakeLists.txt

@@ -221,6 +221,10 @@ if(WIN32)
     set( RT_LIBRARY "winmm" )
 endif(WIN32)    
 
+if (${CMAKE_CXX_COMPILER_ID} STREQUAL "Clang") 
+   set (WARNING_FLAGS "-Wall -Wno-overloaded-virtual")
+endif() 
+
 set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${WARNING_FLAGS} ${MSVC_FLAGS}")
 set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${WARNING_FLAGS} ${MSVC_FLAGS} ${BOOST_CXX_FLAGS}")
 

simgear/CMakeLists.txt

@@ -84,7 +84,8 @@ if(SIMGEAR_SHARED)
             ${ZLIB_LIBRARY} 
             ${OPENSCENEGRAPH_LIBRARIES} 
             ${OPENAL_LIBRARY} ${ALUT_LIBRARY}
-            ${OPENGL_LIBRARY})
+            ${OPENGL_LIBRARY}
+            ${JPEG_LIBRARY})
     
         if(LIBSVN_FOUND)
             target_link_libraries(SimGearScene ${LIBSVN_LIBRARIES})

simgear/misc/sg_dir.cxx

@@ -265,7 +265,7 @@ bool Dir::create(mode_t mode)
     
 // recursively create parent directories
     Dir pr(parent());
-    if (!pr.exists()) {
+    if (!pr.path().isNull() && !pr.exists()) {
         bool ok = pr.create(mode);
         if (!ok) {
             return false;

simgear/scene/material/TextureBuilder.cxx

@@ -216,11 +216,14 @@ TexTuple makeTexTuple(Effect* effect, const SGPropertyNode* props,
     if (pImage)
     {
         imageName = pImage->getStringValue();
-        absFileName = SGModelLib::findDataFile(imageName, options);
+        if (!imageName.empty())
-        if (absFileName.empty())
         {
-            SG_LOG(SG_INPUT, SG_ALERT, "Texture file not found: '"
+            absFileName = SGModelLib::findDataFile(imageName, options);
-                   << imageName << "'");
+            if (absFileName.empty())
+            {
+                SG_LOG(SG_INPUT, SG_ALERT, "Texture file not found: '"
+                       << imageName << "'");
+            }
         }
     }
 

simgear/scene/model/ModelRegistry.cxx

@@ -284,10 +284,10 @@ ModelRegistry::readImage(const string& fileName,
         case GL_COMPRESSED_RED_GREEN_RGTC2_EXT:
         case GL_COMPRESSED_SIGNED_RED_GREEN_RGTC2_EXT:
 
-            SG_LOG(SG_IO, SG_ALERT, "Image \"" << fileName
+            SG_LOG(SG_IO, SG_WARN, "Image \"" << fileName << "\"\n"
-                   << "\" contains non portable compressed textures.\n"
+                   "uses compressed textures which cannot be supported on "
-                   "Usage of these textures depend on an extension that"
+                   "some systems.\n"
-                   " is not guaranteed to be present.");
+                   "Please decompress this texture for improved portability.");
             break;
 
         default: