From fbc47512f3f8e1533a28b4e3eca67938a2f9ebe7 Mon Sep 17 00:00:00 2001 From: Jim Meyering Date: Sun, 4 Jul 2010 10:54:38 +0200 Subject: [PATCH] hash: once again explicitly disallow insertion of NULL * lib/hash.c (hash_insert0): Reinstate just-removed test: inserting a NULL pointer cannot work with these functions. Add a comment with details. This reverts part of the 2010-07-01 commit, 5bef1a35 "hash: extend module to deal with non-pointer keys". --- ChangeLog | 9 +++++++++ lib/hash.c | 9 ++++++++- 2 files changed, 17 insertions(+), 1 deletion(-) diff --git a/ChangeLog b/ChangeLog index 61d0f53c3d..f64cc8ec80 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,12 @@ +2010-07-04 Jim Meyering + + hash: once again explicitly disallow insertion of NULL + * lib/hash.c (hash_insert0): Reinstate just-removed test: + inserting a NULL pointer cannot work with these functions. + Add a comment with details. + This reverts part of the 2010-07-01 commit, 5bef1a35 + "hash: extend module to deal with non-pointer keys". + 2010-07-01 Bruno Haible stdbool: Update doc. diff --git a/lib/hash.c b/lib/hash.c index 4c359a4721..15630be21e 100644 --- a/lib/hash.c +++ b/lib/hash.c @@ -1032,13 +1032,20 @@ hash_rehash (Hash_table *table, size_t candidate) hash_insert, the only way to distinguish those cases is to compare the return value and ENTRY. That works only when you can have two different ENTRY values that point to data that compares "equal". Thus, - when the ENTRY value is a simple scalar, you must use hash_insert0. */ + when the ENTRY value is a simple scalar, you must use hash_insert0. + ENTRY must not be NULL. */ int hash_insert0 (Hash_table *table, void const *entry, void const **matched_ent) { void *data; struct hash_entry *bucket; + /* The caller cannot insert a NULL entry, since hash_lookup returns NULL + to indicate "not found", and hash_find_entry uses "bucket->data == NULL" + to indicate an empty bucket. */ + if (! entry) + abort (); + /* If there's a matching entry already in the table, return that. */ if ((data = hash_find_entry (table, entry, &bucket, false)) != NULL) { -- 2.30.2