fetchFromGitLab: align with fetchFromGitHub

pkgs/build-support/fetchgitlab/default.nix

@@ -1,36 +1,67 @@
 { lib, fetchgit, fetchzip }:
 
 lib.makeOverridable (
-# gitlab example
+{ owner, repo, rev
-{ owner, repo, rev, protocol ? "https", domain ? "gitlab.com", name ? "source", group ? null
+, name ? null # Override with null to use the default value
-, fetchSubmodules ? false, leaveDotGit ? false
+, pname ? lib.concatStringsSep "-" ([ "source" domain ] ++ (lib.optional (group != null) group) ++ [ owner repo ])
+, fetchSubmodules ? false, leaveDotGit ? null
 , deepClone ? false, forceFetchGit ? false
 , sparseCheckout ? []
+, protocol ? "https", domain ? "gitlab.com", group ? null
+, passthru ? { }
+, meta ? { }
 , ... # For hash agility
-} @ args:
+}@args:
 
 let
+  name = if args.name or null != null then args.name
+  else "${pname}-${rev}";
+
+  position = (if args.meta.description or null != null
+    then builtins.unsafeGetAttrPos "description" args.meta
+    else builtins.unsafeGetAttrPos "rev" args
+  );
+  baseUrl = "${protocol}://${domain}/${slug}";
+  newPassthru = passthru // {
+    inherit rev owner repo;
+  };
+  newMeta = meta // {
+    homepage = meta.homepage or baseUrl;
+  } // lib.optionalAttrs (position != null) {
+    # to indicate where derivation originates, similar to make-derivation.nix's mkDerivation
+    position = "${position.file}:${toString position.line}";
+  };
+  passthruAttrs = removeAttrs args [ "protocol" "domain" "owner" "group" "repo" "rev" "fetchSubmodules" "forceFetchGit" "leaveDotGit" "deepClone" ];
   slug = lib.concatStringsSep "/" ((lib.optional (group != null) group) ++ [ owner repo ]);
   escapedSlug = lib.replaceStrings [ "." "/" ] [ "%2E" "%2F" ] slug;
   escapedRev = lib.replaceStrings [ "+" "%" "/" ] [ "%2B" "%25" "%2F" ] rev;
-  passthruAttrs = removeAttrs args [ "protocol" "domain" "owner" "group" "repo" "rev" "fetchSubmodules" "forceFetchGit" "leaveDotGit" "deepClone" ];
+  useFetchGit = fetchSubmodules || (leaveDotGit == true) || deepClone || forceFetchGit || (sparseCheckout != []);
+  # We prefer fetchzip in cases we don't need submodules as the hash
+  # is more stable in that case.
+  fetcher =
+    if useFetchGit then fetchgit
+    # fetchzip may not be overridable when using external tools, for example nix-prefetch
+    else if fetchzip ? override then fetchzip.override { withUnzip = false; }
+    else fetchzip;
 
-  useFetchGit = fetchSubmodules || leaveDotGit || deepClone || forceFetchGit || (sparseCheckout != []);
+  gitRepoUrl = "${baseUrl}.git";
-  fetcher = if useFetchGit then fetchgit else fetchzip;
 
-  gitRepoUrl = "${protocol}://${domain}/${slug}.git";
+  fetcherArgs = (if useFetchGit
+    then {
+      inherit rev deepClone fetchSubmodules sparseCheckout; url = gitRepoUrl;
+      passthru = newPassthru;
+    } // lib.optionalAttrs (leaveDotGit != null) { inherit leaveDotGit; }
+    else {
+      url = "${protocol}://${domain}/api/v4/projects/${escapedSlug}/repository/archive.tar.gz?sha=${escapedRev}";
 
-  fetcherArgs = (if useFetchGit then {
+      passthru = newPassthru // {
-    inherit rev deepClone fetchSubmodules sparseCheckout leaveDotGit;
+        inherit gitRepoUrl;
-    url = gitRepoUrl;
+      };
-  } else {
+    }
-    url = "${protocol}://${domain}/api/v4/projects/${escapedSlug}/repository/archive.tar.gz?sha=${escapedRev}";
+  ) // passthruAttrs // { inherit name; };
-
-    passthru = {
-      inherit gitRepoUrl;
-    };
-  }) // passthruAttrs // { inherit name; };
 in
 
-fetcher fetcherArgs // { meta.homepage = "${protocol}://${domain}/${slug}/"; inherit rev owner repo; }
+(fetcher fetcherArgs).overrideAttrs (finalAttrs: previousAttrs: {
+  meta = newMeta;
+})
 )