ContentSharing: minor tweaks.

modules/juce_gui_basics/filebrowser/juce_ContentSharer.h

@@ -76,7 +76,7 @@ public:
         g.fillEllipse (20, 20, 300, 200);
         Array<Image> images;
         images.add (myImage);
-        ContentSharer::getInstance()->shareImages (images);
+        ContentSharer::getInstance()->shareImages (images, myCallback);
         @endcode
 
         Upon completion you will receive a callback with a sharing result. Note:

modules/juce_gui_basics/native/juce_android_ContentSharer.cpp

@@ -613,7 +613,7 @@ private:
 
     void filesPrepared (jobject fileUris, const StringArray& mimeTypes)
     {
-        auto env = getEnv();
+        auto* env = getEnv();
 
         auto intent = LocalRef<jobject> (env->NewObject (AndroidIntent, AndroidIntent.constructor));
         env->CallObjectMethod (intent, AndroidIntent.setAction,
@@ -698,6 +698,9 @@ private:
 
     static StringArray javaStringArrayToJuceStringArray (const LocalRef<jobjectArray>& javaArray)
     {
+        if (javaArray.get() == 0)
+            return {};
+
         auto* env = getEnv();
 
         const int size = env->GetArrayLength (javaArray.get());
@@ -744,6 +747,17 @@ private:
                                                                                     ParcelFileDescriptor.open,
                                                                                     javaFile.get(), modeReadOnly));
 
+        auto exception = LocalRef<jobject> (env->ExceptionOccurred());
+
+        if (exception != 0)
+        {
+            // Failed to create file descriptor. Have you provided a valid file path/resource name?
+            jassertfalse;
+
+            env->ExceptionClear();
+            return nullptr;
+        }
+
         assetFileDescriptors.add (GlobalRef (LocalRef<jobject> (env->NewObject (AssetFileDescriptor,
                                                                                 AssetFileDescriptor.constructor,
                                                                                 parcelFileDescriptor.get(),