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From: "andreas dot abel at ifi dot lmu dot de" <sourceware-bugzilla@sourceware.org> To: glibc-bugs@sources.redhat.com Subject: [Bug libc/5223] New: tsearch returns node instead of key Date: Sat, 27 Oct 2007 13:56:00 -0000 [thread overview] Message-ID: <20071027135600.5223.andreas.abel@ifi.lmu.de> (raw) [-- Warning: decoded text below may be mangled, UTF-8 assumed --] [-- Attachment #1: Type: text/plain, Size: 2205 bytes --] The specification: http://www.gnu.org/software/libc/manual/html_node/Tree-Search-Function.html#Tree-Search-Function Function: void * tsearch (const void *key, void **rootp, comparison_fn_t compar) ... The return value is a pointer to the matching element in the tree. If a new element was created the pointer points to the new data (which is in fact key). If an entry had to be created and the program ran out of space NULL is returned. However, the implementation does not return the key, but the node. The user does not know of nodes (an internal data structure of search trees), this breakes the abstraction barrier. This is the CVS version from today (1.13): /* Find or insert datum into search tree. KEY is the key to be located, ROOTP is the address of tree root, COMPAR the ordering function. */ void * __tsearch (const void *key, void **vrootp, __compar_fn_t compar) { node q; ... while (*nextp != NULL) { node root = *rootp; r = (*compar) (key, root->key); if (r == 0) return root; /* SHOULD BE root->key !! */ ... } q = (struct node_t *) malloc (sizeof (struct node_t)); if (q != NULL) { *nextp = q; /* link new node to old */ q->key = key; /* initialize new node */ ... } return q; /* SHOULD BE q->keq !! */ } It is hard to believe this bug has survived until today. Yet, the unit test test-tsearch.c does never test whether tsearch run with a new key returns actually this key. Thanks for looking into this, Andreas -- Summary: tsearch returns node instead of key Product: glibc Version: unspecified Status: NEW Severity: normal Priority: P2 Component: libc AssignedTo: drepper at redhat dot com ReportedBy: andreas dot abel at ifi dot lmu dot de CC: andreas dot abel at ifi dot lmu dot de,glibc-bugs at sources dot redhat dot com GCC build triplet: CVS 1.13 (today) http://sourceware.org/bugzilla/show_bug.cgi?id=5223 ------- You are receiving this mail because: ------- You are on the CC list for the bug, or are watching someone who is.
next reply other threads:[~2007-10-27 13:56 UTC|newest] Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top 2007-10-27 13:56 andreas dot abel at ifi dot lmu dot de [this message] 2007-10-27 17:47 ` [Bug libc/5223] " schwab at suse dot de
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