qstr, objstr: Make sure that valid hash != 0, treat 0 as "not computed".
This feature was proposed with initial hashing RFC, and is prerequisite for
seamless static str object definition.
diff --git a/py/qstr.c b/py/qstr.c
index e4b5c11..990ff37 100644
--- a/py/qstr.c
+++ b/py/qstr.c
@@ -35,7 +35,12 @@
for (const byte *top = data + len; data < top; data++) {
hash = ((hash << 5) + hash) ^ (*data); // hash * 33 ^ data
}
- return hash & 0xffff;
+ hash &= 0xffff;
+ // Make sure that valid hash is never zero, zero means "hash not computed"
+ if (hash == 0) {
+ hash++;
+ }
+ return hash;
}
typedef struct _qstr_pool_t {