fix leak when getline fails

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.
This commit is contained in:
NRK 2022-10-31 00:10:45 +06:00 committed by Hiltjo Posthuma
parent e42c036634
commit 689d9bfcf6

View file

@ -554,7 +554,7 @@ readstdin(void)
ssize_t len; ssize_t len;
/* read each line from stdin and add it to the item list */ /* read each line from stdin and add it to the item list */
for (i = 0; (len = getline(&line, &junk, stdin)) != -1; i++, line = NULL) { for (i = 0; (len = getline(&line, &junk, stdin)) != -1; i++) {
if (i + 1 >= size / sizeof *items) if (i + 1 >= size / sizeof *items)
if (!(items = realloc(items, (size += BUFSIZ)))) if (!(items = realloc(items, (size += BUFSIZ))))
die("cannot realloc %zu bytes:", size); die("cannot realloc %zu bytes:", size);
@ -562,7 +562,9 @@ readstdin(void)
line[len - 1] = '\0'; line[len - 1] = '\0';
items[i].text = line; items[i].text = line;
items[i].out = 0; items[i].out = 0;
line = NULL;
} }
free(line);
if (items) if (items)
items[i].text = NULL; items[i].text = NULL;
lines = MIN(lines, i); lines = MIN(lines, i);