do not quote quotes

src/main/java/eu/siacs/conversations/ui/ConversationFragment.java

@@ -74,6 +74,7 @@ import eu.siacs.conversations.ui.adapter.MessageAdapter.OnContactPictureClicked;
 import eu.siacs.conversations.ui.adapter.MessageAdapter.OnContactPictureLongClicked;
 import eu.siacs.conversations.ui.widget.EditMessage;
 import eu.siacs.conversations.ui.widget.ListSelectionManager;
+import eu.siacs.conversations.utils.MessageUtils;
 import eu.siacs.conversations.utils.NickValidityChecker;
 import eu.siacs.conversations.utils.StylingHelper;
 import eu.siacs.conversations.utils.UIHelper;
@@ -591,7 +592,7 @@ public class ConversationFragment extends Fragment implements EditMessage.Keyboa
 	}
 
 	private void quoteMessage(Message message) {
-		quoteText(message.getMergedBody().toString());
+		quoteText(MessageUtils.prepareQuote(message));
 	}
 
 	@Override
@@ -632,7 +633,7 @@ public class ConversationFragment extends Fragment implements EditMessage.Keyboa
 			MenuItem showErrorMessage = menu.findItem(R.id.show_error_message);
 			if (!treatAsFile && !encrypted && !m.isGeoUri() && !m.treatAsDownloadable()) {
 				copyMessage.setVisible(true);
-				quoteMessage.setVisible(true);
+				quoteMessage.setVisible(MessageUtils.prepareQuote(m).length() > 0);
 			}
 			if (m.getEncryption() == Message.ENCRYPTION_DECRYPTION_FAILED) {
 				retryDecryption.setVisible(true);

src/main/java/eu/siacs/conversations/ui/adapter/MessageAdapter.java

@@ -274,8 +274,7 @@ public class MessageAdapter extends ArrayAdapter<Message> implements CopyTextVie
 			viewHolder.indicator.setVisibility(View.VISIBLE);
 		}
 
-		String formatedTime = UIHelper.readableTimeDifferenceFull(getContext(),
+		String formatedTime = UIHelper.readableTimeDifferenceFull(getContext(), message.getMergedTimeSent());
-				message.getMergedTimeSent());
 		if (message.getStatus() <= Message.STATUS_RECEIVED) {
 			if ((filesize != null) && (info != null)) {
 				viewHolder.time.setText(formatedTime + " \u00B7 " + filesize +" \u00B7 " + info);

src/main/java/eu/siacs/conversations/utils/MessageUtils.java

@@ -0,0 +1,54 @@
+/*
+ * Copyright (c) 2017, Daniel Gultsch All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ * list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation and/or
+ * other materials provided with the distribution.
+ *
+ * 3. Neither the name of the copyright holder nor the names of its contributors
+ * may be used to endorse or promote products derived from this software without
+ * specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+package eu.siacs.conversations.utils;
+
+import eu.siacs.conversations.entities.Message;
+
+public class MessageUtils {
+	public static String prepareQuote(Message message) {
+		final StringBuilder builder = new StringBuilder();
+		final String body = message.getMergedBody().toString();
+		for(String line : body.split("\n")) {
+			if (line.length() <= 0) {
+				continue;
+			}
+			final char c = line.charAt(0);
+			if (c == '>' && UIHelper.isPositionFollowedByQuoteableCharacter(line,0)
+					|| (c == '\u00bb' && !UIHelper.isPositionFollowedByQuote(line,0))) {
+				continue;
+			}
+			if (builder.length() != 0 ) {
+				builder.append('\n');
+			}
+			builder.append(line.trim());
+		}
+		return builder.toString();
+	}
+}