Only statics are sure to be set to 0, explicitly initialise globals.
diff --git a/tools/wrc/wrc.c b/tools/wrc/wrc.c
index dde18d9..fb35541 100644
--- a/tools/wrc/wrc.c
+++ b/tools/wrc/wrc.c
@@ -157,9 +157,9 @@
*/
int no_preprocess = 0;
-char *output_name; /* The name given by the -o option */
-char *input_name; /* The name given on the command-line */
-char *temp_name; /* Temporary file for preprocess pipe */
+char *output_name = NULL; /* The name given by the -o option */
+char *input_name = NULL; /* The name given on the command-line */
+char *temp_name = NULL; /* Temporary file for preprocess pipe */
int line_number = 1; /* The current line */
int char_number = 1; /* The current char pos within the line */
