Make MetadataParser more resistent

In this commit:
- Make MetadataParser resistent to blanks
- Convert all CRLF to LF for unified processing
- For HTML processing split on <div> instead of <p> to adapt the parser
  to the new email format we send out to users.

Change-Id: I7e0316915765dab256771467e0e8345ca75802aa

gerrit-acceptance-tests/src/test/java/com/google/gerrit/acceptance/server/mail/MailProcessorIT.java

@@ -285,7 +285,7 @@ public class MailProcessorIT extends AbstractDaemonTest {
         + "Gerrit-MessageType: comment\n"
         + "Gerrit-Comment-Date: "
         + timestamp
-        + "\n";
+        + " \n";
   }
 
   private MailMessage.Builder messageBuilderWithDefaultFields() {

gerrit-server/src/main/java/com/google/gerrit/server/mail/receive/MetadataParser.java

@@ -23,9 +23,14 @@ import com.google.gerrit.server.mail.MailUtil;
 import com.google.gerrit.server.mail.MetadataName;
 import java.sql.Timestamp;
 import java.time.Instant;
+import java.time.format.DateTimeParseException;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /** Parse metadata from inbound email */
 public class MetadataParser {
+  private static final Logger log = LoggerFactory.getLogger(MailProcessor.class.getName());
+
   public static MailMetadata parse(MailMessage m) {
     MailMetadata metadata = new MailMetadata();
     // Find author
@@ -40,8 +45,12 @@ public class MetadataParser {
         String ps = header.substring(toHeaderWithDelimiter(MetadataName.PATCH_SET).length());
         metadata.patchSet = Ints.tryParse(ps);
       } else if (header.startsWith(toHeaderWithDelimiter(MetadataName.TIMESTAMP))) {
-        String ts = header.substring(toHeaderWithDelimiter(MetadataName.TIMESTAMP).length());
+        String ts = header.substring(toHeaderWithDelimiter(MetadataName.TIMESTAMP).length()).trim();
+        try {
           metadata.timestamp = Timestamp.from(MailUtil.rfcDateformatter.parse(ts, Instant::from));
+        } catch (DateTimeParseException e) {
+          log.error("Mail: Error while parsing timestamp from header of message " + m.id(), e);
+        }
       } else if (header.startsWith(toHeaderWithDelimiter(MetadataName.MESSAGE_TYPE))) {
         metadata.messageType =
             header.substring(toHeaderWithDelimiter(MetadataName.MESSAGE_TYPE).length());
@@ -53,18 +62,18 @@ public class MetadataParser {
 
     // If the required fields were not yet found, continue to parse the text
     if (!Strings.isNullOrEmpty(m.textContent())) {
-      String[] lines = m.textContent().split("\n");
+      String[] lines = m.textContent().replace("\r\n", "\n").split("\n");
-      extractFooters(lines, metadata);
+      extractFooters(lines, metadata, m);
       if (metadata.hasRequiredFields()) {
         return metadata;
       }
     }
 
     // If the required fields were not yet found, continue to parse the HTML
-    // HTML footer are contained inside a <p> tag
+    // HTML footer are contained inside a <div> tag
     if (!Strings.isNullOrEmpty(m.htmlContent())) {
-      String[] lines = m.htmlContent().split("</p>");
+      String[] lines = m.htmlContent().replace("\r\n", "\n").split("</div>");
-      extractFooters(lines, metadata);
+      extractFooters(lines, metadata, m);
       if (metadata.hasRequiredFields()) {
         return metadata;
       }
@@ -73,7 +82,7 @@ public class MetadataParser {
     return metadata;
   }
 
-  private static void extractFooters(String[] lines, MailMetadata metadata) {
+  private static void extractFooters(String[] lines, MailMetadata metadata, MailMessage m) {
     for (String line : lines) {
       if (metadata.changeId == null && line.contains(MetadataName.CHANGE_ID)) {
         metadata.changeId = extractFooter(toFooterWithDelimiter(MetadataName.CHANGE_ID), line);
@@ -82,7 +91,11 @@ public class MetadataParser {
             Ints.tryParse(extractFooter(toFooterWithDelimiter(MetadataName.PATCH_SET), line));
       } else if (metadata.timestamp == null && line.contains(MetadataName.TIMESTAMP)) {
         String ts = extractFooter(toFooterWithDelimiter(MetadataName.TIMESTAMP), line);
+        try {
           metadata.timestamp = Timestamp.from(MailUtil.rfcDateformatter.parse(ts, Instant::from));
+        } catch (DateTimeParseException e) {
+          log.error("Mail: Error while parsing timestamp from footer of message " + m.id(), e);
+        }
       } else if (metadata.messageType == null && line.contains(MetadataName.MESSAGE_TYPE)) {
         metadata.messageType =
             extractFooter(toFooterWithDelimiter(MetadataName.MESSAGE_TYPE), line);
@@ -91,6 +104,6 @@ public class MetadataParser {
   }
 
   private static String extractFooter(String key, String line) {
-    return line.substring(line.indexOf(key) + key.length(), line.length());
+    return line.substring(line.indexOf(key) + key.length(), line.length()).trim();
   }
 }

gerrit-server/src/test/java/com/google/gerrit/server/mail/receive/MetadataParserTest.java

@@ -62,11 +62,11 @@ public class MetadataParserTest {
     b.subject("");
 
     StringBuilder stringBuilder = new StringBuilder();
-    stringBuilder.append(toFooterWithDelimiter(MetadataName.CHANGE_ID) + "cid" + "\n");
+    stringBuilder.append(toFooterWithDelimiter(MetadataName.CHANGE_ID) + "cid" + "\r\n");
-    stringBuilder.append(toFooterWithDelimiter(MetadataName.PATCH_SET) + "1" + "\n");
+    stringBuilder.append("> " + toFooterWithDelimiter(MetadataName.PATCH_SET) + "1" + "\n");
     stringBuilder.append(toFooterWithDelimiter(MetadataName.MESSAGE_TYPE) + "comment" + "\n");
     stringBuilder.append(
-        toFooterWithDelimiter(MetadataName.TIMESTAMP) + "Tue, 25 Oct 2016 02:11:35 -0700" + "\n");
+        toFooterWithDelimiter(MetadataName.TIMESTAMP) + "Tue, 25 Oct 2016 02:11:35 -0700" + "\r\n");
     b.textContent(stringBuilder.toString());
 
     Address author = new Address("Diffy", "test@gerritcodereview.com");
@@ -91,15 +91,16 @@ public class MetadataParserTest {
     b.subject("");
 
     StringBuilder stringBuilder = new StringBuilder();
-    stringBuilder.append("<p>" + toFooterWithDelimiter(MetadataName.CHANGE_ID) + "cid" + "</p>");
-    stringBuilder.append("<p>" + toFooterWithDelimiter(MetadataName.PATCH_SET) + "1" + "</p>");
     stringBuilder.append(
-        "<p>" + toFooterWithDelimiter(MetadataName.MESSAGE_TYPE) + "comment" + "</p>");
+        "<div id\"someid\">" + toFooterWithDelimiter(MetadataName.CHANGE_ID) + "cid" + "</div>");
+    stringBuilder.append("<div>" + toFooterWithDelimiter(MetadataName.PATCH_SET) + "1" + "</div>");
     stringBuilder.append(
-        "<p>"
+        "<div>" + toFooterWithDelimiter(MetadataName.MESSAGE_TYPE) + "comment" + "</div>");
+    stringBuilder.append(
+        "<div>"
             + toFooterWithDelimiter(MetadataName.TIMESTAMP)
             + "Tue, 25 Oct 2016 02:11:35 -0700"
-            + "</p>");
+            + "</div>");
     b.htmlContent(stringBuilder.toString());
 
     Address author = new Address("Diffy", "test@gerritcodereview.com");