[TAP] Fix bug: test NULL before formatting a string/text (for an XML document).

src/tap/formatter/VOTableFormat.java

@@ -220,7 +220,7 @@ public class VOTableFormat implements OutputFormat {
 		out.newLine();
 
 		// Indicate that the query has been successfully processed:	[REQUIRED]
-		out.write("<INFO name=\"QUERY_STATUS\" value=\"ERROR\">" + VOSerializer.formatText(message) + "</INFO>");
+		out.write("<INFO name=\"QUERY_STATUS\" value=\"ERROR\">" + (message == null ? "" : VOSerializer.formatText(message)) + "</INFO>");
 		out.newLine();
 
 		// Append the PROVIDER information (if any):	[OPTIONAL]

src/tap/resource/Availability.java

@@ -123,7 +123,8 @@ public class Availability implements TAPResource, VOSIResource {
 
 		// reason/description of the (non-)availability:
 		pw.print("\t<note>");
-		pw.print(VOSerializer.formatText(service.getAvailability()));
+		if (service.getAvailability() != null)
+			pw.print(VOSerializer.formatText(service.getAvailability()));
 		pw.println("</note>");
 
 		pw.println("</availability>");

src/tap/resource/TAP.java

@@ -415,7 +415,7 @@ public class TAP implements VOSIResource {
 
 		// TAP access:
 		xml.append("\t<interface role=\"std\" xsi:type=\"vs:ParamHTTP\">\n");
-		xml.append("\t\t<accessURL use=\"base\">").append(VOSerializer.formatText(getAccessURL())).append("</accessURL>\n");
+		xml.append("\t\t<accessURL use=\"base\">").append((getAccessURL() == null) ? "" : VOSerializer.formatText(getAccessURL())).append("</accessURL>\n");
 		xml.append("\t</interface>\n");
 
 		// Language description:
@@ -678,7 +678,7 @@ public class TAP implements VOSIResource {
 			// Write the error in the response and return the appropriate HTTP status code:
 			errorWriter.writeError(t, response, request, reqID, owner, resourceName);
 			// Log the error:
-			getLogger().logHttp(LogLevel.ERROR, response, reqID, owner, "HTTP " + response.getStatus() + " - Can not complete the execution of the TAP resource \"" + resourceName + "\", because: " + t.getMessage(), t);
+			getLogger().logHttp(LogLevel.ERROR, response, reqID, owner, "HTTP " + response.getStatus() + " - Can not complete the execution of the TAP resource \"" + resourceName + "\"!", t);
 		}finally{
 			// Notify the queue of the asynchronous jobs that a new connection is available:
 			if (resourceName.equalsIgnoreCase(Sync.RESOURCE_NAME) && service.getFactory().countFreeConnections() >= 1)