Merge pull request #152 from seemk/get_rt_fix

Render target + Travis fix

.travis.yml

@@ -3,6 +3,7 @@ before_install:
   - tar xf rust-nightly-x86_64-unknown-linux-gnu.tar.gz
 install:
   - sudo ./rust-nightly-x86_64-unknown-linux-gnu/install.sh
+  - export LD_LIBRARY_PATH="/usr/local/lib/:$LD_LIBRARY_PATH"
   - wget http://www.libsdl.org/release/SDL2-2.0.0.tar.gz
   - tar -zxvf SDL2-2.0.0.tar.gz
   - cd SDL2-2.0.0

src/sdl2/render.rs

@@ -370,13 +370,13 @@ impl<S> Renderer<S> {
         }
     }
 
-    pub fn get_render_target(&self) -> SdlResult<Texture> {
+    pub fn get_render_target(&self) -> Option<Texture> {
         let raw = unsafe { ll::SDL_GetRenderTarget(self.raw) };
 
         if raw == ptr::null() {
-            Err(get_error())
+            None
         } else {
-            Ok(Texture{
+            Some(Texture{
                 raw: raw,
                 owned: false
             })