unprotbas: error if protecting vars but there are none, or protecting code but there is none.

1 files changed, 14 insertions, 5 deletions

diff --git a/unprotbas.c b/unprotbas.c
index 14fdc63..686b8c3 100644
--- a/unprotbas.c
+++ b/unprotbas.c
@@ -238,9 +238,13 @@ void breakcode(void) {
 		}
 	}
 
-	data[oldpos + 2] = 0;
-	if(verbose)
-		fprintf(stderr, "set invalid line length 0 at line %d, file offset %04x\n", lineno, oldpos + 2);
+	if(!oldpos) {
+		die("can't protect code because there are no lines of code");
+	} else {
+		data[oldpos + 2] = 0;
+		if(verbose)
+			fprintf(stderr, "set invalid line length 0 at line %d, file offset %04x\n", lineno, oldpos + 2);
+	}
 }
 
 /* sometimes the variable name table isn't large enough to hold
@@ -581,8 +585,13 @@ void scramble_vars(void) {
 	for(i = vnstart; i < vvstart - 1; i++)
 		data[i] = '\x9b';
 
-	if(verbose)
-		fprintf(stderr, "replaced %d byte variable name table with EOLs.\n", i);
+	if(verbose) {
+		i -= vnstart;
+		if(i)
+			fprintf(stderr, "replaced %d byte variable name table with EOLs.\n", i);
+		else
+			die("can't protect variables because there are no variables.");
+	}
 }
 
 void print_help(void) {