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.

diff --git a/dmenu.c b/dmenu.c
index e7be8af98b94dca791b00707df4c51067c5bfea8..e786d7a31ba7ec360e057db1f5321b73073d39e4 100644 (file)
--- a/dmenu.c
+++ b/dmenu.c
@@ -554,7 +554,7 @@ readstdin(void)
        ssize_t len;
 
        /* 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 (!(items = realloc(items, (size += BUFSIZ))))
                                die("cannot realloc %zu bytes:", size);
@@ -562,7 +562,9 @@ readstdin(void)
                        line[len - 1] = '\0';
                items[i].text = line;
                items[i].out = 0;
+               line = NULL;
        }
+       free(line);
        if (items)
                items[i].text = NULL;
        lines = MIN(lines, i);