fix text selection crash on older Androids (#4166)

I hate these workarounds for Android bugs, I'm always afraid the will
introduce other problems. I tested this on multiple Android versions, it
definitely fixes the problem and otherwise seems fine though.

closes #4164

app/src/main/java/com/keylesspalace/tusky/view/ClickableSpanTextView.kt

@@ -25,6 +25,9 @@ import android.graphics.Paint
 import android.graphics.Path
 import android.graphics.Rect
 import android.graphics.RectF
+import android.os.Build
+import android.text.Selection
+import android.text.Spannable
 import android.text.Spanned
 import android.text.style.ClickableSpan
 import android.text.style.URLSpan
@@ -192,6 +195,26 @@ class ClickableSpanTextView @JvmOverloads constructor(
         }
     }
 
+    override fun dispatchTouchEvent(event: MotionEvent): Boolean {
+        // workaround to https://code.google.com/p/android/issues/detail?id=191430
+        // from https://stackoverflow.com/a/36740247
+        if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.O_MR1) {
+            val startSelection = selectionStart
+            val endSelection = selectionEnd
+
+            val content = text
+            if (startSelection < 0 || endSelection < 0) {
+                Selection.setSelection(content as Spannable?, content.length)
+            } else if (startSelection != endSelection) {
+                if (event.actionMasked == ACTION_DOWN) {
+                    text = null
+                    text = content
+                }
+            }
+        }
+        return super.dispatchTouchEvent(event)
+    }
+
     /**
      * Handle some touch events.
      *