websrv_lib: handle general failures with http 500 status

If some http request fails with an unhandled exception, it is better
to send back the 500 error and close the connection, not leave the client
waiting for a response.

bzr revid: p_christ@hol.gr-20100726093335-o0p4ibon2uvfjxxn

bin/service/websrv_lib.py

@@ -230,7 +230,17 @@ class MultiHTTPHandler(FixSendError,BaseHTTPRequestHandler):
             return
         fore.close_connection = 0
         method = getattr(fore, mname)
-        method()
+        try:
+            method()
+        except Exception, e:
+            self.log_error("Could not run %s: %s" % (mname, e))
+            fore.send_error(500, "Internal error")
+            # may not work if method has already sent data
+            fore.close_connection = 1
+            if hasattr(fore, '_flush'):
+                fore._flush()
+            return
+        
         if fore.close_connection:
             # print "Closing connection because of handler"
             self.close_connection = fore.close_connection