handle merge commits

app/src/lib/components/BranchFilesList.svelte

@@ -1,6 +1,8 @@
 <script lang="ts">
 	import BranchFilesHeader from './BranchFilesHeader.svelte';
+	import Button from './Button.svelte';
 	import FileListItem from './FileListItem.svelte';
+	import { copyToClipboard } from '$lib/utils/clipboard';
 	import { getContext } from '$lib/utils/context';
 	import { selectFilesInList } from '$lib/utils/selectFilesInList';
 	import { maybeMoveSelection } from '$lib/utils/selection';
@@ -46,9 +48,28 @@
 		currentDisplayIndex += 1;
 		displayedFiles = [...displayedFiles, ...chunkedFiles[currentDisplayIndex]];
 	}
+	let mergeDiffCommand = 'git diff-tree --cc ';
 </script>
 
-<BranchFilesHeader {title} {files} {showCheckboxes} />
+{#if !$commit?.isMergeCommit()}
+	<BranchFilesHeader {title} {files} {showCheckboxes} />
+{:else}
+	<div
+		class="text-base-11"
+		style="padding-left: 1rem; padding-right: 1rem; color: var(--clr-scale-ntrl-50); "
+	>
+		<span style="font-style: italic;">Merge commit diff:</span>
+		<br />
+		<span style="font-family: monospace; user-select: text;"
+			>{mergeDiffCommand + $commit.id.slice(0, 7)}</span
+		>
+		<Button
+			size="tag"
+			icon="copy"
+			on:mousedown={() => copyToClipboard(mergeDiffCommand + $commit.id.slice(0, 7))}
+		></Button>
+	</div>
+{/if}
 {#each displayedFiles as file (file.id)}
 	<FileListItem
 		{file}

app/src/lib/vbranches/types.ts

@@ -194,6 +194,10 @@ export class Commit {
 	isParentOf(possibleChild: Commit) {
 		return possibleChild.parentIds.includes(this.id);
 	}
+
+	isMergeCommit() {
+		return this.parentIds.length > 1;
+	}
 }
 
 export function isLocalCommit(obj: any): obj is Commit {
@@ -208,6 +212,7 @@ export class RemoteCommit {
 	createdAt!: Date;
 	changeId!: string;
 	isSigned!: boolean;
+	parentIds!: string[];
 
 	parent?: RemoteCommit;
 	children?: RemoteCommit[];
@@ -228,6 +233,10 @@ export class RemoteCommit {
 	get status(): CommitStatus {
 		return 'upstream';
 	}
+
+	isMergeCommit() {
+		return this.parentIds.length > 1;
+	}
 }
 
 export function isRemoteCommit(obj: any): obj is RemoteCommit {

crates/gitbutler-core/src/virtual_branches/remote.rs

@@ -1,4 +1,4 @@
-use std::path::Path;
+use std::{os::unix::process::parent_id, path::Path};
 
 use anyhow::{Context, Result};
 use bstr::BString;
@@ -48,6 +48,7 @@ pub struct RemoteCommit {
     pub created_at: u128,
     pub author: Author,
     pub change_id: Option<String>,
+    pub parent_ids: Vec<git::Oid>,
 }
 
 // for legacy purposes, this is still named "remote" branches, but it's actually
@@ -187,12 +188,20 @@ pub fn branch_to_remote_branch_data(
 }
 
 pub fn commit_to_remote_commit(commit: &git2::Commit) -> RemoteCommit {
+    let parent_ids: Vec<git::Oid> = commit
+        .parents()
+        .map(|c| {
+            let c: git::Oid = c.id().into();
+            c
+        })
+        .collect::<Vec<_>>();
     RemoteCommit {
         id: commit.id().to_string(),
         description: commit.message_bstr().to_owned(),
         created_at: commit.time().seconds().try_into().unwrap(),
         author: commit.author().into(),
         change_id: commit.change_id(),
+        parent_ids,
     }
 }