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Commit 16c45930 authored by unknown's avatar unknown
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BUG 11104 (same as changeset 1.1891 on the 5.0 tree, but realised this 

needed to be fixed in earlier versions)
Fixed the iteration of how substrings are handled with negative indexes in 
SUBSTRING_INDEX


mysql-test/r/func_str.result:
  New results for the fix to substring_index
mysql-test/t/func_str.test:
  Added tests for fix to substring_index, various lenth search patterns. Also included
  are the queuries the user who reported the bug listed in the bug report
sql/item_strfunc.cc:
  Fix to BUG 11104 
      Took out the offset-=delimiter_length-1 out of the for loop. It was causing
      basically this: 
      select substring_index('the king of the the hill', 'the', -2) to not work.
      The first iteration, offset would be initialised to 24, then strstr would 
      point at 'the king of the the* hill' ('*'means right before the 
      character following), returning a offset of 16. The for loop would then 
      decrement offset by two (3 - 1), to 14, now pointing at 
      "the king of th*e the hill", _skipping_ past the 'e' in the second to last
      'the', and therefore strstr would never have a chance of matching the 
      second to last 'the', then moving on to the 'the' at the begginning of the 
      string!
  
      In a nutshell, offset was being decremented by too great a value, preventing
      the second to last 'the' from being ever found, hence the result of 
      'king of the the hill' from the query that is reported in the bug report
parent 90e41fac
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Showing with 170 additions and 2 deletions
mysql-test/r/func_str.result
View file @ 16c45930
......@@ -38,6 +38,123 @@ www. .se
select substring_index('.tcx.se','.',-2),substring_index('.tcx.se','.tcx',-1);
substring_index('.tcx.se','.',-2) substring_index('.tcx.se','.tcx',-1)
tcx.se .se
select substring_index('aaaaaaaaa1','a',1);
substring_index('aaaaaaaaa1','a',1)
select substring_index('aaaaaaaaa1','aa',1);
substring_index('aaaaaaaaa1','aa',1)
select substring_index('aaaaaaaaa1','aa',2);
substring_index('aaaaaaaaa1','aa',2)
aa
select substring_index('aaaaaaaaa1','aa',3);
substring_index('aaaaaaaaa1','aa',3)
aaaa
select substring_index('aaaaaaaaa1','aa',4);
substring_index('aaaaaaaaa1','aa',4)
aaaaaa
select substring_index('aaaaaaaaa1','aa',5);
substring_index('aaaaaaaaa1','aa',5)
aaaaaaaaa1
select substring_index('aaaaaaaaa1','aaa',1);
substring_index('aaaaaaaaa1','aaa',1)
select substring_index('aaaaaaaaa1','aaa',2);
substring_index('aaaaaaaaa1','aaa',2)
aaa
select substring_index('aaaaaaaaa1','aaa',3);
substring_index('aaaaaaaaa1','aaa',3)
aaaaaa
select substring_index('aaaaaaaaa1','aaa',4);
substring_index('aaaaaaaaa1','aaa',4)
aaaaaaaaa1
select substring_index('aaaaaaaaa1','aaaa',1);
substring_index('aaaaaaaaa1','aaaa',1)
select substring_index('aaaaaaaaa1','aaaa',2);
substring_index('aaaaaaaaa1','aaaa',2)
aaaa
select substring_index('aaaaaaaaa1','1',1);
substring_index('aaaaaaaaa1','1',1)
aaaaaaaaa
select substring_index('aaaaaaaaa1','a',-1);
substring_index('aaaaaaaaa1','a',-1)
1
select substring_index('aaaaaaaaa1','aa',-1);
substring_index('aaaaaaaaa1','aa',-1)
1
select substring_index('aaaaaaaaa1','aa',-2);
substring_index('aaaaaaaaa1','aa',-2)
aa1
select substring_index('aaaaaaaaa1','aa',-3);
substring_index('aaaaaaaaa1','aa',-3)
aaaa1
select substring_index('aaaaaaaaa1','aa',-4);
substring_index('aaaaaaaaa1','aa',-4)
aaaaaa1
select substring_index('aaaaaaaaa1','aa',-5);
substring_index('aaaaaaaaa1','aa',-5)
aaaaaaaaa1
select substring_index('aaaaaaaaa1','aaa',-1);
substring_index('aaaaaaaaa1','aaa',-1)
1
select substring_index('aaaaaaaaa1','aaa',-2);
substring_index('aaaaaaaaa1','aaa',-2)
aaa1
select substring_index('aaaaaaaaa1','aaa',-3);
substring_index('aaaaaaaaa1','aaa',-3)
aaaaaa1
select substring_index('aaaaaaaaa1','aaa',-4);
substring_index('aaaaaaaaa1','aaa',-4)
select substring_index('the king of thethe hill','the',-2);
substring_index('the king of thethe hill','the',-2)
the hill
select substring_index('the king of the the hill','the',-2);
substring_index('the king of the the hill','the',-2)
the hill
select substring_index('the king of the the hill','the',-2);
substring_index('the king of the the hill','the',-2)
the hill
select substring_index('the king of the the hill',' the ',-1);
substring_index('the king of the the hill',' the ',-1)
hill
select substring_index('the king of the the hill',' the ',-2);
substring_index('the king of the the hill',' the ',-2)
the hill
select substring_index('the king of the the hill',' ',-1);
substring_index('the king of the the hill',' ',-1)
hill
select substring_index('the king of the the hill',' ',-2);
substring_index('the king of the the hill',' ',-2)
the hill
select substring_index('the king of the the hill',' ',-3);
substring_index('the king of the the hill',' ',-3)
the hill
select substring_index('the king of the the hill',' ',-4);
substring_index('the king of the the hill',' ',-4)
the the hill
select substring_index('the king of the the hill',' ',-5);
substring_index('the king of the the hill',' ',-5)
of the the hill
select substring_index('the king of the.the hill','the',-2);
substring_index('the king of the.the hill','the',-2)
.the hill
select substring_index('the king of thethethe.the hill','the',-3);
substring_index('the king of thethethe.the hill','the',-3)
the.the hill
select substring_index('the king of thethethe.the hill','the',-1);
substring_index('the king of thethethe.the hill','the',-1)
hill
select substring_index('the king of the the hill','the',1);
substring_index('the king of the the hill','the',1)
select substring_index('the king of the the hill','the',2);
substring_index('the king of the the hill','the',2)
the king of
select substring_index('the king of the the hill','the',3);
substring_index('the king of the the hill','the',3)
the king of the
select concat(':',ltrim(' left '),':',rtrim(' right '),':');
concat(':',ltrim(' left '),':',rtrim(' right '),':')
:left : right:
......
mysql-test/t/func_str.test
View file @ 16c45930
......@@ -19,6 +19,45 @@ select concat('',left(right(concat('what ',concat('is ','happening')),9),4),'',s
select substring_index('www.tcx.se','.',-2),substring_index('www.tcx.se','.',1);
select substring_index('www.tcx.se','tcx',1),substring_index('www.tcx.se','tcx',-1);
select substring_index('.tcx.se','.',-2),substring_index('.tcx.se','.tcx',-1);
select substring_index('aaaaaaaaa1','a',1);
select substring_index('aaaaaaaaa1','aa',1);
select substring_index('aaaaaaaaa1','aa',2);
select substring_index('aaaaaaaaa1','aa',3);
select substring_index('aaaaaaaaa1','aa',4);
select substring_index('aaaaaaaaa1','aa',5);
select substring_index('aaaaaaaaa1','aaa',1);
select substring_index('aaaaaaaaa1','aaa',2);
select substring_index('aaaaaaaaa1','aaa',3);
select substring_index('aaaaaaaaa1','aaa',4);
select substring_index('aaaaaaaaa1','aaaa',1);
select substring_index('aaaaaaaaa1','aaaa',2);
select substring_index('aaaaaaaaa1','1',1);
select substring_index('aaaaaaaaa1','a',-1);
select substring_index('aaaaaaaaa1','aa',-1);
select substring_index('aaaaaaaaa1','aa',-2);
select substring_index('aaaaaaaaa1','aa',-3);
select substring_index('aaaaaaaaa1','aa',-4);
select substring_index('aaaaaaaaa1','aa',-5);
select substring_index('aaaaaaaaa1','aaa',-1);
select substring_index('aaaaaaaaa1','aaa',-2);
select substring_index('aaaaaaaaa1','aaa',-3);
select substring_index('aaaaaaaaa1','aaa',-4);
select substring_index('the king of thethe hill','the',-2);
select substring_index('the king of the the hill','the',-2);
select substring_index('the king of the the hill','the',-2);
select substring_index('the king of the the hill',' the ',-1);
select substring_index('the king of the the hill',' the ',-2);
select substring_index('the king of the the hill',' ',-1);
select substring_index('the king of the the hill',' ',-2);
select substring_index('the king of the the hill',' ',-3);
select substring_index('the king of the the hill',' ',-4);
select substring_index('the king of the the hill',' ',-5);
select substring_index('the king of the.the hill','the',-2);
select substring_index('the king of thethethe.the hill','the',-3);
select substring_index('the king of thethethe.the hill','the',-1);
select substring_index('the king of the the hill','the',1);
select substring_index('the king of the the hill','the',2);
select substring_index('the king of the the hill','the',3);
select concat(':',ltrim(' left '),':',rtrim(' right '),':');
select concat(':',trim(LEADING FROM ' left'),':',trim(TRAILING FROM ' right '),':');
......
sql/item_strfunc.cc
View file @ 16c45930
......@@ -1084,11 +1084,23 @@ String *Item_func_substr_index::val_str(String *str)
}
}
else
{ // Start counting at end
for (offset=res->length() ; ; offset-=delimeter_length-1)
{
/*
Negative index, start counting at the end
*/
for (offset=res->length(); offset ;)
{
/*
this call will result in finding the position pointing to one
address space less than where the found substring is located
in res
*/
if ((int) (offset=res->strrstr(*delimeter,offset)) < 0)
return res; // Didn't find, return org string
/*
At this point, we've searched for the substring
the number of times as supplied by the index value
*/
if (!++count)
{
offset+=delimeter_length;
......
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