From 509a9cee1ca110f6186f25a9cc85889e0918fa13 Mon Sep 17 00:00:00 2001 From: Sergey Vojtovich Date: Thu, 23 Apr 2009 16:24:08 +0500 Subject: BUG#42907 - Multi-term boolean fulltext query containing a single quote fails in 5.1.x Performing fulltext prefix search (a word with truncation operator) may cause a dead-loop. The problem was in smarter index merge algorithm - it was writing record reference to an incorrect memory area. mysql-test/r/fulltext.result: A test case for BUG#42907. mysql-test/t/fulltext.test: A test case for BUG#42907. storage/myisam/ft_boolean_search.c: Fixed incorrect memory update by _mi_dpointer() when performing fulltext prefix search. --- storage/myisam/ft_boolean_search.c | 21 +++++++++++++++++++-- 1 file changed, 19 insertions(+), 2 deletions(-) (limited to 'storage') diff --git a/storage/myisam/ft_boolean_search.c b/storage/myisam/ft_boolean_search.c index 66097864622..58363894cff 100644 --- a/storage/myisam/ft_boolean_search.c +++ b/storage/myisam/ft_boolean_search.c @@ -335,7 +335,23 @@ static int _ftb_no_dupes_cmp(void* not_used __attribute__((unused)), return CMP_NUM((*((my_off_t*)a)), (*((my_off_t*)b))); } -/* returns 1 if the search was finished (must-word wasn't found) */ +/* + When performing prefix search (a word with truncation operator), we + must preserve original prefix to ensure that characters which may be + expanded/contracted do not break the prefix. This is done by storing + newly found key immediatly after the original word in ftbw->word + buffer. + + ftbw->word= LENGTH WORD [ LENGTH1 WORD1 ] WEIGHT REFERENCE + LENGTH - 1 byte, length of the WORD + WORD - LENGTH bytes, the word itself + LENGTH1 - 1 byte, length of the WORD1, present in case of prefix search + WORD1 - LENGTH bytes, the word itself, present in case of prefix search + WEIGHT - 4 bytes (HA_FT_WLEN), either weight or number of subkeys + REFERENCE - rec_reflength bytes, pointer to the record + + returns 1 if the search was finished (must-word wasn't found) +*/ static int _ft2_search(FTB *ftb, FTB_WORD *ftbw, my_bool init_search) { int r; @@ -369,7 +385,8 @@ static int _ft2_search(FTB *ftb, FTB_WORD *ftbw, my_bool init_search) if (ftbw->docid[0] < max_docid) { sflag|= SEARCH_SAME; - _mi_dpointer(info, (uchar *)(ftbw->word + ftbw->len + HA_FT_WLEN), + _mi_dpointer(info, (uchar*) (lastkey_buf + HA_FT_WLEN + + (ftbw->off ? 0 : lastkey_buf[0] + 1)), max_docid); } r=_mi_search(info, ftbw->keyinfo, (uchar*) lastkey_buf, -- cgit v1.2.1