Bug 28160: Values from 150$a aren't prefilled in z39.50 search form from an existing authority record

For names and uniform titles, when you do a z39.50 search from an authority
record, we prefill what's in the relevant tag's subfield a in the search
form, but for subjects, we don't, both because GetMandatoryFieldZ3950 thinks
the param is topic when it's actually subject, and because
z3950_auth_search.tt doesn't bother putting the value of &subject into the
form.

Test plan:

1) Authorities - New authority - Topical Term
2) Tab 1, click on HEADING-TOPICAL TERM to expand subfields
3) In subfield a, type goats
4) Click Z39.50/SRU search and verify that the Subject heading search field
   has goats prefilled

Signed-off-by: Owen Leonard <oleonard@myacpl.org>

Signed-off-by: Nick Clemens <nick@bywatersolutions.com>

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>

authorities/authorities.pl

@@ -336,7 +336,7 @@ sub GetMandatoryFieldZ3950 {
             '110a' => 'authorcorp',
             '111a' => 'authormeetingcon',
             '130a' => 'uniformtitle',
-            '150a' => 'topic',
+            '150a' => 'subject',
         };
     }else{
         return {

koha-tmpl/intranet-tmpl/prog/en/modules/cataloguing/z3950_auth_search.tt

@@ -39,7 +39,7 @@
                 <div class="row">
                     <fieldset class="rows">
                     <ol>
-                        <li><label for="subject">Subject heading: </label> <input type="text" id="subject" name="subject" value="" /></li>
+                        <li><label for="subject">Subject heading: </label> <input type="text" id="subject" name="subject" value="[% subject | html %]" /></li>
                         <li><label for="subjectsubdiv">Subject sub-division: </label> <input type="text" id="subjectsubdiv" name="subjectsubdiv" value="" /></li>
                         <li><label for="title">Title (any): </label> <input type="text" id="title"  name="title" value="[% title | html %]" /></li>
                         <li><label for="uniformtitle">Title (uniform): </label> <input type="text" id="uniformtitle"  name="uniformtitle" value="[% uniformtitle | html %]" /></li>