Add a check for invalid spans being set by SpellChecker.

One of the exit conditions of the loop immediately above the code is
when a BreakIterator finishes its input and emits BreakIterator.DONE,
which we were then mistakenly then using as a parameter for setting
spans.

Bug: 12936072
Bug: 5555929
Change-Id: Ib4aba113f2e7838cd040076160c1dd0fb90adb1a

core/java/android/widget/SpellChecker.java

@@ -727,14 +727,10 @@ public class SpellChecker implements SpellCheckerSessionListener {
                 }
             }
 
-            if (scheduleOtherSpellCheck && wordStart <= end) {
+            if (scheduleOtherSpellCheck && wordStart != BreakIterator.DONE && wordStart <= end) {
                 // Update range span: start new spell check from last wordStart
                 setRangeSpan(editable, wordStart, end);
             } else {
-                if (DBG && scheduleOtherSpellCheck) {
-                    Log.w(TAG, "Trying to schedule spellcheck for invalid region, from "
-                            + wordStart + " to " + end);
-                }
                 removeRangeSpan(editable);
             }