blob2xex: warn on address wraparound.

1 files changed, 8 insertions, 1 deletions

diff --git a/blob2xex.c b/blob2xex.c
index 0f17371..413fb52 100644
--- a/blob2xex.c
+++ b/blob2xex.c
@@ -99,8 +99,12 @@ int write_segment(
 	}
 
 	/* make sure we don't wrap the Atari's address space. */
-	if(size + loadaddr > 0xffff)
+	if(size + loadaddr > 0xffff) {
+		int oldsize = size;
 		size = (size - loadaddr) + 1;
+		fprintf(stderr, SELF ": "
+				"warning: %s: address would exceed $FFFF! truncated %d bytes to %d.\n", infile, oldsize, size);
+	}
 
 	/* read <size> bytes, or until EOF (which is not an error) */
 	while(size) {
@@ -209,6 +213,7 @@ int main(int argc, char **argv) {
 			if( (bytes = write_segment(infile, outfile, loadaddr, initaddr, offset, size)) ) {
 				segcount++;
 				loadaddr += bytes;
+				loadaddr %= 0xffff;
 			} else {
 				segcount = 0;
 				break;
@@ -245,6 +250,8 @@ int main(int argc, char **argv) {
 			fprintf(stderr, SELF ": read %d input files, wrote %d segments to %s.\n",
 					incount, segcount, outfile);
 	} else {
+		if(xex_verbose)
+			fprintf(stderr, SELF ": no output file created, due to fatal error.\n");
 		unlink(outfile);
 		return 1;
 	}