2 files changed, 94 insertions, 2 deletions
diff --git a/java/src/com/android/inputmethod/latin/RichInputConnection.java b/java/src/com/android/inputmethod/latin/RichInputConnection.java
index fa7f23efb..925381b50 100644
--- a/java/src/com/android/inputmethod/latin/RichInputConnection.java
+++ b/java/src/com/android/inputmethod/latin/RichInputConnection.java
@@ -607,8 +607,11 @@ public final class RichInputConnection {
             }
         }
 
-        return new TextRange(TextUtils.concat(before, after), startIndexInBefore,
-                before.length() + endIndexInAfter, before.length());
+        // We don't use TextUtils#concat because it copies all spans without respect to their
+        // nature. If the text includes a PARAGRAPH span and it has been split, then
+        // TextUtils#concat will crash when it tries to concat both sides of it.
+        return new TextRange(StringUtils.concatWithNonParagraphSuggestionSpansOnly(before, after),
+                startIndexInBefore, before.length() + endIndexInAfter, before.length());
     }
 
     public boolean isCursorTouchingWord(final SettingsValues settingsValues) {
diff --git a/java/src/com/android/inputmethod/latin/utils/StringUtils.java b/java/src/com/android/inputmethod/latin/utils/StringUtils.java
index 121aecf0f..327780ad0 100644
--- a/java/src/com/android/inputmethod/latin/utils/StringUtils.java
+++ b/java/src/com/android/inputmethod/latin/utils/StringUtils.java
@@ -20,7 +20,12 @@ import com.android.inputmethod.annotations.UsedForTesting;
 import com.android.inputmethod.latin.Constants;
 import com.android.inputmethod.latin.settings.SettingsValues;
 
+import android.text.Spannable;
+import android.text.SpannableString;
+import android.text.Spanned;
+import android.text.SpannedString;
 import android.text.TextUtils;
+import android.text.style.SuggestionSpan;
 import android.util.JsonReader;
 import android.util.JsonWriter;
 import android.util.Log;
@@ -462,4 +467,88 @@ public final class StringUtils {
         }
         return "";
     }
+
+    /**
+     * Copies the spans from the region <code>start...end</code> in
+     * <code>source</code> to the region
+     * <code>destoff...destoff+end-start</code> in <code>dest</code>.
+     * Spans in <code>source</code> that begin before <code>start</code>
+     * or end after <code>end</code> but overlap this range are trimmed
+     * as if they began at <code>start</code> or ended at <code>end</code>.
+     * Only SuggestionSpans that don't have the SPAN_PARAGRAPH span are copied.
+     *
+     * This code is almost entirely taken from {@link TextUtils#copySpansFrom}, except for the
+     * kind of span that is copied.
+     *
+     * @throws IndexOutOfBoundsException if any of the copied spans
+     * are out of range in <code>dest</code>.
+     */
+    public static void copyNonParagraphSuggestionSpansFrom(Spanned source, int start, int end,
+                                     Spannable dest, int destoff) {
+        Object[] spans = source.getSpans(start, end, SuggestionSpan.class);
+
+        for (int i = 0; i < spans.length; i++) {
+            int fl = source.getSpanFlags(spans[i]);
+            if (0 != (fl & Spannable.SPAN_PARAGRAPH)) continue;
+
+            int st = source.getSpanStart(spans[i]);
+            int en = source.getSpanEnd(spans[i]);
+
+            if (st < start)
+                st = start;
+            if (en > end)
+                en = end;
+
+            dest.setSpan(spans[i], st - start + destoff, en - start + destoff,
+                         fl);
+        }
+    }
+
+    /**
+     * Returns a CharSequence concatenating the specified CharSequences, retaining their
+     * SuggestionSpans that don't have the PARAGRAPH flag, but not other spans.
+     *
+     * This code is almost entirely taken from {@link TextUtils#concat(CharSequence...)}, except
+     * it calls copyNonParagraphSuggestionSpansFrom instead of {@link TextUtils#copySpansFrom}.
+     */
+    public static CharSequence concatWithNonParagraphSuggestionSpansOnly(CharSequence... text) {
+        if (text.length == 0) {
+            return "";
+        }
+
+        if (text.length == 1) {
+            return text[0];
+        }
+
+        boolean spanned = false;
+        for (int i = 0; i < text.length; i++) {
+            if (text[i] instanceof Spanned) {
+                spanned = true;
+                break;
+            }
+        }
+
+        StringBuilder sb = new StringBuilder();
+        for (int i = 0; i < text.length; i++) {
+            sb.append(text[i]);
+        }
+
+        if (!spanned) {
+            return sb.toString();
+        }
+
+        SpannableString ss = new SpannableString(sb);
+        int off = 0;
+        for (int i = 0; i < text.length; i++) {
+            int len = text[i].length();
+
+            if (text[i] instanceof Spanned) {
+                copyNonParagraphSuggestionSpansFrom((Spanned) text[i], 0, len, ss, off);
+            }
+
+            off += len;
+        }
+
+        return new SpannedString(ss);
+    }
 }