Bug 11479: Remove experimental given/when keywords

Replace constructs using given and when by if/else
feature now generates compilation warnings in 5.18
and is liable to change behaviour.

This patch:

* replaces the construct with if/else
* reformats the if branching using perltidy
  to remove the now redundant indent

To test:

[1] Verify that prove -v t/db_dependent/MarcModificationTemplates.t
    passes.

Signed-off-by: Chris Cormack <chris@bigballofwax.co.nz>
Signed-off-by: Jonathan Druart <jonathan.druart@biblibre.com>
Signed-off-by: Galen Charlton <gmc@esilibrary.com>

C4/MarcModificationTemplates.pm

@@ -547,49 +547,59 @@ sub ModifyRecordWithTemplate {
         );
 
         my $do = 1;
-        if ( $conditional ) {
-            for ( $conditional_comparison ) {
-                when ( /^exists$/ ) {
-                    my $exists = field_exists( $record, $conditional_field, $conditional_subfield );
-                    $do = $conditional eq 'if'
-                        ? $exists
-                        : not $exists;
-                }
-                when ( /^not_exists$/ ) {
-                    my $exists = field_exists( $record, $conditional_field, $conditional_subfield );
-                    $do = $conditional eq 'if'
-                        ? not $exists
-                        : $exists;
-                }
-                when ( /^equals$/ ) {
-                    my $equals = field_equals( $record, $conditional_value, $conditional_field, $conditional_subfield, $conditional_regex );
-                    $do = $conditional eq 'if'
-                        ? $equals
-                        : not $equals;
-                }
-                when ( /^not_equals$/ ) {
-                    my $equals = field_equals( $record, $conditional_value, $conditional_field, $conditional_subfield, $conditional_regex );
-                    $do = $conditional eq 'if'
-                        ? not $equals
-                        : $equals;
-                }
+        if ($conditional) {
+            if ( $conditional_comparison eq 'exists' ) {
+                my $exists = field_exists( $record, $conditional_field,
+                    $conditional_subfield );
+                $do =
+                    $conditional eq 'if'
+                  ? $exists
+                  : not $exists;
+            }
+            elsif ( $conditional_comparison eq 'not_exists' ) {
+                my $exists = field_exists( $record, $conditional_field,
+                    $conditional_subfield );
+                $do =
+                  $conditional eq 'if'
+                  ? not $exists
+                  : $exists;
+            }
+            elsif ( $conditional_comparison eq 'equals' ) {
+                my $equals = field_equals(
+                    $record,            $conditional_value,
+                    $conditional_field, $conditional_subfield,
+                    $conditional_regex
+                );
+                $do =
+                    $conditional eq 'if'
+                  ? $equals
+                  : not $equals;
+            }
+            elsif ( $conditional_comparison eq 'not_equals' ) {
+                my $equals = field_equals(
+                    $record,            $conditional_value,
+                    $conditional_field, $conditional_subfield,
+                    $conditional_regex
+                );
+                $do =
+                  $conditional eq 'if'
+                  ? not $equals
+                  : $equals;
             }
         }
 
-        if ( $do ) {
-            for ( $action ) {
-                when ( /^copy_field$/ ) {
-                    copy_field( @params );
-                }
-                when ( /^update_field$/ ) {
-                    update_field( @params );
-                }
-                when ( /^move_field$/ ) {
-                    move_field( @params );
-                }
-                when ( /^delete_field$/ ) {
-                    delete_field( @params );
-                }
+        if ($do) {
+            if ( $action eq 'copy_field' ) {
+                copy_field(@params);
+            }
+            elsif ( $action eq 'update_field' ) {
+                update_field(@params);
+            }
+            elsif ( $action eq 'move_field' ) {
+                move_field(@params);
+            }
+            elsif ( $action eq 'delete_field' ) {
+                delete_field(@params);
             }
         }