Bug 12522 - Fatal database error when viewing Holds for Bib with no Items

This patch fixes some potential SQL syntax errors, which can cause
fatal software errors in Koha when the environmental variable DEBUG
is on.

_TEST PLAN_

Before applying:

0) Ensure that you don't have "SetEnv DEBUG 1" in your Apache config
1) Create a new bib record
2) Click on the "Holds" tab before creating any items
3) Note the message "Cannot place hold: this record has no
items attached."

4) Add "SetEnv DEBUG 1" to your Apache config
5) Restart Apache
6) Refresh your page
7) Note the following Software Error: "DBD::mysql::st execute failed:
You have an error in your SQL syntax; check the manual that
corresponds to your MariaDB server version for the right syntax to
use near ')' at line 3 at /koha/lib/C4/Koha.pm line 835.

8) Apply the patch

9) Refresh your page
10) Note the message from Step 3

Thorough tester:

11) Remove "SetEnv DEBUG 1" from your Apache config, restart Apache,
and refresh your page. You should see the message from Step 3.

Signed-off-by: Bernardo Gonzalez Kriegel <bgkriegel@gmail.com>
Error reproduced, patch fixes it.
Tested following test plan, no koha-qa errors.

Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>

C4/Biblio.pm

@@ -1074,13 +1074,15 @@ sub GetBiblio {
 sub GetBiblioItemInfosOf {
     my @biblioitemnumbers = @_;
 
-    my $query = '
+    my $biblioitemnumber_values = @biblioitemnumbers ? join( ',', @biblioitemnumbers ) : "''";
+
+    my $query = "
         SELECT biblioitemnumber,
             publicationyear,
             itemtype
         FROM biblioitems
-        WHERE biblioitemnumber IN (' . join( ',', @biblioitemnumbers ) . ')
-    ';
+        WHERE biblioitemnumber IN ($biblioitemnumber_values)
+    ";
     return get_infos_of( $query, 'biblioitemnumber' );
 }
 

C4/Items.pm

@@ -1145,11 +1145,13 @@ sub GetItemsCount {
 sub GetItemInfosOf {
     my @itemnumbers = @_;
 
-    my $query = '
+    my $itemnumber_values = @itemnumbers ? join( ',', @itemnumbers ) : "''";
+
+    my $query = "
         SELECT *
         FROM items
-        WHERE itemnumber IN (' . join( ',', @itemnumbers ) . ')
-    ';
+        WHERE itemnumber IN ($itemnumber_values)
+    ";
     return get_infos_of( $query, 'itemnumber' );
 }