prevent overwriting input file (not foolproof) and remove tabs

adpcm-xq.c

@@ -113,14 +113,14 @@ int main (argc, argv) int argc; char **argv;
                         fprintf (stderr, "\nillegal option: %c !\n", **argv);
                         return 1;
                 }
-	else if (!infilename) {
+        else if (!infilename) {
             infilename = malloc (strlen (*argv) + 10);
             strcpy (infilename, *argv);
-	}
-	else if (!outfilename) {
+        }
+        else if (!outfilename) {
             outfilename = malloc (strlen (*argv) + 10);
             strcpy (outfilename, *argv);
-	}
+        }
         else {
             fprintf (stderr, "\nextra unknown argument: %s !\n", *argv);
             return 1;
@@ -135,6 +135,11 @@ int main (argc, argv) int argc; char **argv;
         return 0;
     }
 
+    if (!strcmp (infilename, outfilename)) {
+        fprintf (stderr, "can't overwrite input file (specify different/new output file name)\n");
+        return -1;
+    }
+
     if (!overwrite && (outfile = fopen (outfilename, "r"))) {
         fclose (outfile);
         fprintf (stderr, "output file \"%s\" exists (use -y to overwrite)\n", outfilename);