[PATCH pve-storage v1 29/54] plugin: simplify recently refactored logic in parse_volname method

["Max R. Carrara" <m.carrara@proxmox.com>]

Pull the if-clause with the definedness check out and make it a guard
clause, die-ing early if parsing fails.

Sum up the if-clauses of the `iso`, `vztmpl` and `snippets` volume
types, since their bodies have an identical pattern.

Keep the branches for the `backup` and `import` volume types separate.

Since the guard clause now already `die`s on a parsing failure, extend
the error message of the final `die` at the end of the method, stating
that the volume type is unhandled. This should never be hit unless we
introduce a new volume type and happen to forget to handle it in this
method.

Signed-off-by: Max R. Carrara <m.carrara@proxmox.com>
---
 src/PVE/Storage/Plugin.pm | 48 +++++++++++++++++----------------------
 1 file changed, 21 insertions(+), 27 deletions(-)

diff --git a/src/PVE/Storage/Plugin.pm b/src/PVE/Storage/Plugin.pm
index a3cb1343..376e2515 100644
--- a/src/PVE/Storage/Plugin.pm
+++ b/src/PVE/Storage/Plugin.pm
@@ -821,37 +821,31 @@ sub parse_volname {
         return ('images', $name, $vmid, undef, undef, $isBase, $format);
     }

-    if (defined(my $parts = parse_volname_as_parts($volname))) {
-        my ($vtype, $volume_path) = $parts->@{qw(vtype path)};
+    my $parts = parse_volname_as_parts($volname);
+    die "unable to parse directory volume name '$volname'\n"
+        if !defined($parts);

-        if ($vtype eq 'iso') {
-            return ($vtype, $volume_path, undef, undef, undef, undef, 'raw');
-        }
+    my ($vtype, $volume_path) = $parts->@{qw(vtype path)};

-        if ($vtype eq 'vztmpl') {
-            return ($vtype, $volume_path, undef, undef, undef, undef, 'raw');
-        }
-
-        if ($vtype eq 'backup') {
-            return ($vtype, $volume_path, $parts->{vmid}, undef, undef, undef, 'raw');
-        }
-
-        if ($vtype eq 'snippets') {
-            return ($vtype, $volume_path, undef, undef, undef, undef, 'raw');
-        }
-
-        if ($vtype eq 'import') {
-            my $format = $parts->{ext};
-
-            if (defined(my $content_ext = $parts->{'content-ext'})) {
-                $format .= "+$content_ext";
-            }
-
-            return ($vtype, $volume_path, undef, undef, undef, undef, $format);
-        }
+    if ($vtype eq 'iso' || $vtype eq 'vztmpl' || $vtype eq 'snippets') {
+        return ($vtype, $volume_path, undef, undef, undef, undef, 'raw');
     }

-    die "unable to parse directory volume name '$volname'\n";
+    if ($vtype eq 'backup') {
+        return ($vtype, $volume_path, $parts->{vmid}, undef, undef, undef, 'raw');
+    }
+
+    if ($vtype eq 'import') {
+        my $format = $parts->{ext};
+
+        if (defined(my $content_ext = $parts->{'content-ext'})) {
+            $format .= "+$content_ext";
+        }
+
+        return ($vtype, $volume_path, undef, undef, undef, undef, $format);
+    }
+
+    die "unable to parse directory volume name '$volname' - unhandled volume type '$vtype'\n";
 }

 # FIXME: remove on the next APIAGE reset.
--
2.47.3