kc3-lang/SDL

diff --git a/android-project/app/src/main/java/org/libsdl/app/SDLActivity.java b/android-project/app/src/main/java/org/libsdl/app/SDLActivity.java
index 05b83db..32d9446 100644
--- a/android-project/app/src/main/java/org/libsdl/app/SDLActivity.java
+++ b/android-project/app/src/main/java/org/libsdl/app/SDLActivity.java
@@ -1923,7 +1923,7 @@ class SDLSurface extends SurfaceView implements SurfaceHolder.Callback,
     @Override
     public boolean onTouch(View v, MotionEvent event) {
         /* Ref: http://developer.android.com/training/gestures/multi.html */
-        final int touchDevId = event.getDeviceId();
+        int touchDevId = event.getDeviceId();
         final int pointerCount = event.getPointerCount();
         int action = event.getActionMasked();
         int pointerFingerId;
@@ -1931,6 +1931,16 @@ class SDLSurface extends SurfaceView implements SurfaceHolder.Callback,
         int i = -1;
         float x,y,p;
 
+        /**
+         * Prevent id to be -1, since it's used in SDL internal for synthetic events
+         * Appears when using Android emulator, eg:
+         *  adb shell input mouse tap 100 100
+         *  adb shell input touchscreen tap 100 100
+         */
+        if (touchDevId < 0) {
+            touchDevId -= 1;
+        }
+
         // 12290 = Samsung DeX mode desktop mouse
         // 12290 = 0x3002 = 0x2002 | 0x1002 = SOURCE_MOUSE | SOURCE_TOUCHSCREEN
         // 0x2   = SOURCE_CLASS_POINTER