util: Make the initial allocation bigger for xreadlinkat()

Most symlinks are more than 1 character long, so rather than wasting
time with 1, 2, 4, ... when we don't have a good guess for the length,
start with a bigger one.

Credit to https://twitter.com/RichFelker/status/1306321019108556806 for
reminding me of this.

1 files changed, 6 insertions, 1 deletions

diff --git a/util.c b/util.c
index 0ac1f7a..715396c 100644
--- a/util.c
+++ b/util.c
@@ -59,10 +59,15 @@ int xreaddir(DIR *dir, struct dirent **de) {
 }
 
 char *xreadlinkat(int fd, const char *path, size_t size) {
-	++size; // NUL-terminator
 	ssize_t len;
 	char *name = NULL;
 
+	if (size == 0) {
+		size = 64;
+	} else {
+		++size; // NUL terminator
+	}
+
 	while (true) {
 		char *new_name = realloc(name, size);
 		if (!new_name) {