FIxes issues with open prior blame command

- Adds proper error handling & messaging
  - Handles uncommitted lines
Adds open prior blame to hover on uncommitted lines

src/commands/openFileAtRevision.ts

@@ -54,17 +54,41 @@ export class OpenFileAtRevisionCommand extends ActiveEditorCommand {
 		if (context.command === Commands.OpenBlamePriorToChange) {
 			args = { ...args, annotationType: FileAnnotationType.Blame };
 			if (args.revisionUri == null && context.editor != null) {
-				const blameline = context.editor.selection.active.line;
-				if (blameline >= 0) {
+				const editorLine = context.editor.selection.active.line;
+				if (editorLine >= 0) {
 					try {
 						const gitUri = await GitUri.fromUri(context.editor.document.uri);
-						const blame = await Container.instance.git.getBlameForLine(gitUri, blameline);
-						if (blame != null && !blame.commit.isUncommitted && blame.commit.previousSha != null) {
-							args.revisionUri = GitUri.toRevisionUri(GitUri.fromCommit(blame.commit, true));
+						const blame = await Container.instance.git.getBlameForLine(gitUri, editorLine);
+						if (blame != null) {
+							if (blame.commit.isUncommitted) {
+								const diffUris = await blame.commit.getPreviousLineDiffUris(
+									gitUri,
+									editorLine,
+									gitUri.sha,
+								);
+								if (diffUris?.previous != null) {
+									args.revisionUri = GitUri.toRevisionUri(diffUris.previous);
+								} else {
+									void Messages.showCommitHasNoPreviousCommitWarningMessage(blame.commit);
+									return undefined;
+								}
+							} else if (blame?.commit.previousSha != null) {
+								args.revisionUri = GitUri.toRevisionUri(GitUri.fromCommit(blame.commit, true));
+							} else {
+								void Messages.showCommitHasNoPreviousCommitWarningMessage(blame.commit);
+								return undefined;
+							}
 						}
-					} catch {}
+					} catch (ex) {
+						Logger.error(ex, 'OpenBlamePriorToChangeCommand');
+					}
 				}
 			}
+
+			if (args.revisionUri == null) {
+				void Messages.showGenericErrorMessage('Unable to open blame');
+				return undefined;
+			}
 		}
 
 		return this.execute(context.editor, context.uri, args);

src/git/formatters/commitFormatter.ts

@@ -294,6 +294,12 @@ export class CommitFormatter extends Formatter {
 					repoPath: this._item.repoPath,
 					line: this._options.editor?.line,
 				})} "Open Changes with Previous Revision")`;
+
+				commands += `   [$(versions)](${OpenFileAtRevisionCommand.getMarkdownCommandArgs(
+					GitUri.toRevisionUri(diffUris.previous),
+					FileAnnotationType.Blame,
+					this._options.editor?.line,
+				)} "Open Blame Prior to this Change")`;
 			} else {
 				commands = `\`${this._padOrTruncate(
 					GitRevision.shorten(

src/hovers/hovers.ts

@@ -37,6 +37,7 @@ export namespace Hovers {
 				}
 			} else {
 				ref = commit.previousSha;
+				if (ref == null) return undefined;
 			}
 
 			const line = editorLine + 1;
@@ -73,9 +74,7 @@ export namespace Hovers {
 		let current;
 		if (commit.isUncommitted) {
 			const diffUris = await commit.getPreviousLineDiffUris(uri, editorLine, documentRef);
-			if (diffUris == null || diffUris.previous == null) {
-				return undefined;
-			}
+			if (diffUris?.previous == null) return undefined;
 
 			message = `[$(compare-changes)](${DiffWithCommand.getMarkdownCommandArgs({
 				lhs: {