git.stevedylan.dev

fix leak when getline fails 689d9bfc

according to the getline(3) documentation, the calling code needs to
free the buffer even if getline fails.

dmenu currently doesn't do that which results in a small leak in case of
failure (e.g when piped /dev/null)

	$ ./dmenu < /dev/null
	==8201==ERROR: LeakSanitizer: detected memory leaks
	Direct leak of 120 byte(s) in 1 object(s) allocated from:
	    #0 0x7f6bf5785ef7 in malloc
	    #1 0x7f6bf538ec84 in __getdelim
	    #2 0x405d0c in readstdin dmenu.c:557

moving `line = NULL` inside the loop body wasn't strictly necessary, but
IMO it makes it more apparent that `line` is getting cleared to NULL
after each successful iteration.

NRK · 2022-10-31 00:10 1 file(s) · +3 −1

554	554		ssize_t len;
555	555
556	556		/* read each line from stdin and add it to the item list */
557		-	for (i = 0; (len = getline(&line, &junk, stdin)) != -1; i++, line = NULL) {
	557	+	for (i = 0; (len = getline(&line, &junk, stdin)) != -1; i++) {
558	558		if (i + 1 >= size / sizeof *items)
559	559		if (!(items = realloc(items, (size += BUFSIZ))))
560	560		die("cannot realloc %zu bytes:", size);

562	562		line[len - 1] = '\0';
563	563		items[i].text = line;
564	564		items[i].out = 0;
	565	+	line = NULL;
565	566		}
	567	+	free(line);
566	568		if (items)
567	569		items[i].text = NULL;
568	570		lines = MIN(lines, i);