Bug 10271: fix searching using an index containing "ns" or "nb"

Bug 10271: fix searching using an index containing "ns" or "nb"

When an index does not contain a structure part, the structure "wrdl"
is automatically added and a structure is mandatory to build search
query (to convert ':' into '=').

But the code that tests that the structure is not already defined looks
in entire index string :

  $index =~ /(st-|phr|ext|wrdl|nb|ns)/

It should look for a comma followed by a structure and in the case of
"nb" and "ns" look for an exact match.

The consequence is that an index containing ns or nb or phr or etc does
not work.

This patch modifies the regexp for this part and other parts looking at
structures into index.

Test plan :
- Desactivate all searching sysprefs.
- Create a new index called "ansa" number 8999 into bib1.att,
  ccl.properties and records.abs
- Index a biblio with a value on this index, ie "VALUE"
- Perform a search on this index by editing URL:
  http://<server>/cgi-bin/koha/catalogue/search.pl?idx=ansa&q=VALUE
=> Without patch, the search does not work. The PQF query is
   "@and ansa: VALUE"
=> With patch, the search works. The PQF query is "@attr 1=8999 VALUE";
- Perform same test with an index containing a structure ie "aphra"
- Set QueryAutoTruncate syspref to automatically
=> Check * is added to operand : PQF query is
   "@attr 1=8999 @attr 4=6 @attr 5=1 VALUE"
- You may check stopwords removal but this feature is obsolete

Signed-off-by: Bernardo Gonzalez Kriegel <bgkriegel@gmail.com>
Comment: as far as I can test, this works. Small tab error reported
by koha-qa, fixed in a followup.

This kind of patch is difficult to test without explicit instructions,
not everyone knows how to check what kind of PQF search is used.
I don't know. But I can test search results.

Test:
1) Deactivate search sysprefs
QueryAutoTruncate = only if * is added
QueryFuzzy = Don't try
QueryStemming = Don't try
QueryWeightFields = Disable
UseQueryParser = Do not try

2) Create new index 'ansa'
bib1.att : att 8999 ansa
ccl.properties : ansa 1=8999
records.abs : melm 999 ansa:w,ansa:p

1) and 2) from comment 3 on Bug

3) In the undestanding that index refers to field 999,
edited default framework, made 999a visible on editor

4) Edit sample record, add 'VALUE' to 999a, save, reindex

5) Search with /cgi-bin/koha/catalogue/search.pl?idx=ansa&q=VALUE
No results

6) Apply patch, repeat search
Got results

That's all I can test. If not enough for QA, then this
must wait until further and explicit test instructions

Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
There is (for MARC21, at least), an exising indexes that this patch
fixes: Code-institution.

Signed-off-by: Galen Charlton <gmc@esilibrary.com>
(cherry picked from commit e17abe0e2891cc420581ebe998e1c8444ba844d3)
Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>