Adds protection for deleted SHA

Author: eamodio

src/hovers/hovers.ts

@@ -11,7 +11,7 @@ import type { GitCommit } from '../git/models/commit';
 import type { GitLineDiff, ParsedGitDiffHunk } from '../git/models/diff';
 import type { PullRequest } from '../git/models/pullRequest';
 import type { GitRemote } from '../git/models/remote';
-import { uncommittedStaged } from '../git/models/revision';
+import { deletedOrMissing, uncommittedStaged } from '../git/models/revision';
 import type { RemoteProvider } from '../git/remotes/remoteProvider';
 import { isUncommittedStaged, shortenRevision } from '../git/utils/revision.utils';
 import { configuration } from '../system/-webview/configuration';
@@ -111,7 +111,7 @@ export async function changesMessage(
 		message = `[$(compare-changes)](${DiffWithCommand.createMarkdownCommandLink(commit, range)} "Open Changes")`;
 
 		previousSha ??= await commit.getPreviousSha();
-		if (previousSha) {
+		if (previousSha && previousSha !== deletedOrMissing) {
 			previous = `   [$(git-commit) ${shortenRevision(
 				previousSha,
 			)}](${ShowQuickCommitCommand.createMarkdownCommandLink(previousSha)} "Show Commit")  ${