alloc: fix bug in tiny allocator

We can have a 0 byte in the *middle* of an encoding.

diff --git a/ccan/alloc/tiny.c b/ccan/alloc/tiny.c
index b965eb471b329f9ff4108513f0cf10a6796c8928..feffa618e0cf629d9edc1822ed89d70ba8dde290 100755 (executable)
--- a/ccan/alloc/tiny.c
+++ b/ccan/alloc/tiny.c
@@ -152,13 +152,13 @@ static bool long_enough(unsigned long offset, unsigned long len,
 
 static unsigned long find_free_end(unsigned char *arr, unsigned long arrsize)
 {
-       unsigned long end;
+       long i;
 
-       for (end = 0; end < arrsize; end++) {
-               if (!arr[end])
-                       break;
+       for (i = arrsize-1; i >= 0; i--) {
+               if (arr[i])
+                       return i + 1;
        }
-       return end;
+       return 0;
 }
 
 void *tiny_alloc_get(void *pool, unsigned long poolsize,