rpc: Prefix output with 'error' if command error occurs

rpc.patch

Index: src/server/tcl_server.c
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/src/server/tcl_server.c b/src/server/tcl_server.c
--- a/src/server/tcl_server.c	(revision 53556fcded056aa62ffdc6bf0c97bff87d891dab)
+++ b/src/server/tcl_server.c	(revision 68ca08d3330564db706a66c6de01c0ae5056fad5)
@@ -183,6 +183,8 @@
 	unsigned char in[256];
 	char *tc_line_new;
 	int tc_line_size_new;
+	int command_result;
+	char error_buf[32];
 
 	rlen = connection_read(connection, &in, sizeof(in));
 	if (rlen <= 0) {
@@ -241,8 +243,13 @@
 #undef ESTR
 		} else {
 			tclc->tc_line[tclc->tc_lineoffset-1] = '\0';
-			command_run_line(connection->cmd_ctx, tclc->tc_line);
+			command_result = command_run_line(connection->cmd_ctx, tclc->tc_line);
 			result = Jim_GetString(Jim_GetResult(interp), &reslen);
+			if (command_result != ERROR_OK) {
+				/* send an error message */
+				snprintf(error_buf, sizeof(error_buf), "error %i: ", command_result);
+				tcl_output(connection, error_buf, strlen(error_buf));
+			}
 			retval = tcl_output(connection, result, reslen);
 			if (retval != ERROR_OK)
 				return retval;