d2: preserve leading comment spacing

patches/d2/402_preserve_leading_comment_spacing.patch

@@ -0,0 +1,23 @@
+diff --git a/d2format/format.go b/d2format/format.go
+index 754e3302..a45d55f6 100644
+--- a/d2format/format.go
++++ b/d2format/format.go
+@@ -76,17 +76,17 @@ func (p *printer) node(n d2ast.Node) {
+ 		p.edgeIndex(n)
+ 	}
+ }
+ 
+ func (p *printer) comment(c *d2ast.Comment) {
+ 	lines := strings.Split(c.Value, "\n")
+ 	for i, line := range lines {
+ 		p.sb.WriteString("#")
+-		if line != "" && !strings.HasPrefix(line, " ") {
++		if line != "" {
+ 			p.sb.WriteByte(' ')
+ 		}
+ 		p.sb.WriteString(line)
+ 		if i < len(lines)-1 {
+ 			p.newline()
+ 		}
+ 	}
+ }

pkgs/d2.nix

@@ -27,7 +27,9 @@ buildGoModule {
 
   nativeBuildInputs = [ installShellFiles ];
 
-  patches = [ ];
+  patches = [
+    ../patches/d2/402_preserve_leading_comment_spacing.patch
+  ];
 
   postInstall = "installManPage ci/release/template/man/d2.1";