Index: mupdf-1.10a-source/source/tools/mudraw.c
===================================================================
--- mupdf-1.10a-source.orig/source/tools/mudraw.c
+++ mupdf-1.10a-source/source/tools/mudraw.c
@@ -720,7 +720,7 @@ static void dodrawpage(fz_context *ctx,
 		char buf[512];
 		fz_output *out;
 
-		if (!strcmp(output, "-"))
+		if (!output || !strcmp(output, "-"))
 			out = fz_stdout(ctx);
 		else
 		{