commit da9f6a725261e3df1a0f0d340d3e365ee5abe9ea
Author: Marko Kangas <marko.kangas@bitfactor.fi>
Date:   Thu Sep 21 12:49:58 2017 +0300

    Fix broken back button with SwiftKey keyboard
    
    Ignore keyboard visibility when back button pressed. This is dirty hack
    to fix missing visibility event from SwiftKey keyboard.
    
    Task-number: QTBUG-39006
    Change-Id: I1cde44add2008b8b801863f98051978b32ac32f6

diff --git a/src/android/jar/src/org/qtproject/qt5/android/QtActivityDelegate.java b/src/android/jar/src/org/qtproject/qt5/android/QtActivityDelegate.java
index 26f877235f..7bda4a91e5 100644
--- a/src/android/jar/src/org/qtproject/qt5/android/QtActivityDelegate.java
+++ b/src/android/jar/src/org/qtproject/qt5/android/QtActivityDelegate.java
@@ -1133,7 +1133,7 @@ public class QtActivityDelegate
 
         m_lastChar = lc;
         if (keyCode == KeyEvent.KEYCODE_BACK) {
-            m_backKeyPressedSent = !m_keyboardIsVisible;
+            m_backKeyPressedSent = true;
             if (!m_backKeyPressedSent)
                 return true;
         }