From 0f39b4f2cd4e11f728f65179d3432f5d0dbcf883 Mon Sep 17 00:00:00 2001
From: Ladislau Szomoru <3372902+lszomoru@users.noreply.github.com>
Date: Tue, 13 May 2025 14:39:49 +0000
Subject: [PATCH] SCM Graph - fix edge case for commit margin (#248821)

---
 .../workbench/contrib/scm/browser/scmHistory.ts  | 16 ++++++++++++++++
 .../contrib/scm/browser/scmHistoryViewPane.ts    |  8 +++-----
 2 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/src/vs/workbench/contrib/scm/browser/scmHistory.ts b/src/vs/workbench/contrib/scm/browser/scmHistory.ts
index fbe1f7a4c33..8f74a15cae7 100644
--- a/src/vs/workbench/contrib/scm/browser/scmHistory.ts
+++ b/src/vs/workbench/contrib/scm/browser/scmHistory.ts
@@ -353,3 +353,19 @@ export function toISCMHistoryItemViewModelArray(
 
 	return viewModels;
 }
+
+export function getHistoryItemColor(historyItemViewModel: ISCMHistoryItemViewModel): string {
+	const historyItem = historyItemViewModel.historyItem;
+	const inputSwimlanes = historyItemViewModel.inputSwimlanes;
+	const outputSwimlanes = historyItemViewModel.outputSwimlanes;
+
+	// Find the history item in the input swimlanes
+	const inputIndex = inputSwimlanes.findIndex(node => node.id === historyItem.id);
+
+	// Circle index - use the input swimlane index if present, otherwise add it to the end
+	const circleIndex = inputIndex !== -1 ? inputIndex : inputSwimlanes.length;
+
+	// Circle color - use the output swimlane color if present, otherwise the input swimlane color
+	return circleIndex < outputSwimlanes.length ? outputSwimlanes[circleIndex].color :
+		circleIndex < inputSwimlanes.length ? inputSwimlanes[circleIndex].color : historyItemRefColor;
+}
diff --git a/src/vs/workbench/contrib/scm/browser/scmHistoryViewPane.ts b/src/vs/workbench/contrib/scm/browser/scmHistoryViewPane.ts
index b2944968bc7..75a51aaca63 100644
--- a/src/vs/workbench/contrib/scm/browser/scmHistoryViewPane.ts
+++ b/src/vs/workbench/contrib/scm/browser/scmHistoryViewPane.ts
@@ -31,7 +31,7 @@ import { asCssVariable, ColorIdentifier, foreground } from '../../../../platform
 import { IThemeService } from '../../../../platform/theme/common/themeService.js';
 import { IViewPaneOptions, ViewAction, ViewPane, ViewPaneShowActions } from '../../../browser/parts/views/viewPane.js';
 import { IViewDescriptorService, ViewContainerLocation } from '../../../common/views.js';
-import { renderSCMHistoryItemGraph, toISCMHistoryItemViewModelArray, SWIMLANE_WIDTH, renderSCMHistoryGraphPlaceholder, historyItemHoverDeletionsForeground, historyItemHoverLabelForeground, historyItemHoverAdditionsForeground, historyItemHoverDefaultLabelForeground, historyItemHoverDefaultLabelBackground, historyItemRefColor } from './scmHistory.js';
+import { renderSCMHistoryItemGraph, toISCMHistoryItemViewModelArray, SWIMLANE_WIDTH, renderSCMHistoryGraphPlaceholder, historyItemHoverDeletionsForeground, historyItemHoverLabelForeground, historyItemHoverAdditionsForeground, historyItemHoverDefaultLabelForeground, historyItemHoverDefaultLabelBackground, getHistoryItemColor } from './scmHistory.js';
 import { getHistoryItemEditorTitle, getProviderKey, isSCMHistoryItemChangeViewModelTreeElement, isSCMHistoryItemLoadMoreTreeElement, isSCMHistoryItemViewModelTreeElement, isSCMRepository } from './util.js';
 import { ISCMHistoryItem, ISCMHistoryItemChange, ISCMHistoryItemRef, ISCMHistoryItemViewModel, ISCMHistoryProvider, SCMHistoryItemChangeViewModelTreeElement, SCMHistoryItemLoadMoreTreeElement, SCMHistoryItemViewModelTreeElement } from '../common/history.js';
 import { HISTORY_VIEW_PANE_ID, ISCMProvider, ISCMRepository, ISCMService, ISCMViewService } from '../common/scm.js';
@@ -414,8 +414,7 @@ class HistoryItemRenderer implements ITreeRenderer<SCMHistoryItemViewModelTreeEl
 		});
 		templateData.elementDisposables.add(historyItemHover);
 
-		const color = historyItemViewModel.inputSwimlanes.find(s => s.id === historyItem.id)?.color;
-		templateData.margin.style.borderLeftColor = asCssVariable(color ?? historyItemRefColor);
+		templateData.margin.style.borderLeftColor = asCssVariable(getHistoryItemColor(historyItemViewModel));
 
 		templateData.graphContainer.textContent = '';
 		templateData.graphContainer.classList.toggle('current', historyItemViewModel.isCurrent);
@@ -672,8 +671,7 @@ class HistoryItemChangeRenderer implements ITreeRenderer<SCMHistoryItemChangeVie
 		const historyItemViewModel = element.element.historyItemViewModel;
 		const historyItemChange = element.element.historyItemChange;
 
-		const color = historyItemViewModel.inputSwimlanes.find(s => s.id === historyItemViewModel.historyItem.id)?.color;
-		templateData.margin.style.borderLeftColor = asCssVariable(color ?? historyItemRefColor);
+		templateData.margin.style.borderLeftColor = asCssVariable(getHistoryItemColor(historyItemViewModel));
 
 		templateData.graphPlaceholder.textContent = '';
 		templateData.graphPlaceholder.style.width = `${SWIMLANE_WIDTH * (element.element.graphColumns.length + 1)}px`;