ci(release): refuse empty assets and verify what the release serves

Assisted-by: DeepSeek V4.1 Flash

.gitea/workflows/release.yml

@@ -325,6 +325,17 @@ jobs:
             chomp $id;
             my @files = grep { -f $_ } glob(q{dist/*/*});
             @files or die qq{ERROR: no assets under dist/\n};
+            # A file that arrived empty from the artifact step would be uploaded as an
+            # empty attachment, every status would still be 201, and the run would go
+            # green over a release nobody can install.  Refuse it here, before the
+            # upload, and verify what was stored afterwards.
+            my %size;
+            for my $path (@files) {
+              my $n = -s $path // 0;
+              (my $name = $path) =~ s{.*/}{};
+              $n > 0 or die qq{ERROR: $path is empty, so there is nothing to upload\n};
+              $size{$name} = $n;
+            }
             my $bad = 0;
             for my $path (@files) {
               (my $name = $path) =~ s{.*/}{};
@@ -346,5 +357,31 @@ jobs:
               printf qq{%s: HTTP %s\n}, $name, $code;
               $bad = 1 if $code ne q{201};
             }
+            # Read every asset back through the release download route and require the
+            # served length to be the file that was sent: stored but empty is a broken
+            # release however green the run looks.
+            open(my $v, q{<}, q{version-no-v.txt}) or die qq{version-no-v.txt: $!};
+            my $v = <$v>;
+            close($v);
+            chomp $v;
+            for my $name (sort keys %size) {
+              my $url = qq{$ENV{GITEA_SERVER_URL}/$ENV{GITEA_REPOSITORY}/releases/download/v$v/$name};
+              my @head = (q{curl}, q{-sS}, q{-I}, q{-H}, qq{Authorization: token $ENV{GITEA_TOKEN}}, $url);
+              open(my $h, q{-|}, @head) or die qq{curl: $!};
+              my $len;
+              my $status;
+              while (my $l = <$h>) {
+                $status = $1 if $l =~ m{^HTTP/\S+\s+(\d+)};
+                $len = $1 if $l =~ m{^content-length:\s*(\d+)}i;
+              }
+              my $ok = close($h);
+              $len = defined $len ? $len : 0;
+              if (!$ok || $status != 200 || $len != $size{$name}) {
+                printf qq{ERROR: %s serves %s bytes, expected %d\n}, $name, $len, $size{$name};
+                $bad = 1;
+                next;
+              }
+              printf qq{%s: serves %d bytes\n}, $name, $len;
+            }
             exit($bad ? 1 : 0);
           '