Report error when unable to read attribute name.

Report validation errors, if any, when reading an IPP message in the unit test
program.

Author: michaelrsweet

cups/ipp.c

@@ -5609,6 +5609,7 @@ ipp_read_io(void        *src,		// I - Data source
 	    // New attribute; read the name and add it...
 	    if ((*cb)(src, buffer, (size_t)n) < n)
 	    {
+	      _cupsSetError(IPP_STATUS_ERROR_INTERNAL, _("Unable to read IPP attribute name."), 1);
 	      DEBUG_puts("1ipp_read_io: unable to read name.");
 	      goto rollback;
 	    }
@@ -5965,6 +5966,8 @@ ipp_read_io(void        *src,		// I - Data source
   // attribute read in order to keep the IPP message valid...
   rollback:
 
+  DEBUG_puts("1ipp_read_io: <<rollback>>");
+
   _cupsBufferRelease((char *)buffer);
 
   if (attr)

cups/testipp.c

@@ -866,7 +866,7 @@ main(int  argc,				// I - Number of command-line arguments
 
       if (request)
       {
-	printf("\n%s:\n", argv[i]);
+	printf("\n%s: %s\n", argv[i], ippValidateAttributes(request) ? "OK" : cupsGetErrorString());
 	print_attributes(request, 4);
 	ippDelete(request);
       }