Merge f8567d04a0e039a50ef7020303bbfed4492e3a36 into 98ef79d73a6a546241dd02959ae17f136369b604

templates/repo/diff/blob_excerpt.tmpl

@@ -11,7 +11,7 @@
 			</td>
 		{{else}}
 			{{$inlineDiff := $.section.GetComputedInlineDiffFor $line ctx.Locale}}
-			<td class="lines-num lines-num-old" data-line-num="{{if $line.LeftIdx}}{{$line.LeftIdx}}{{end}}"><span rel="{{if $line.LeftIdx}}diff-{{$.FileNameHash}}L{{$line.LeftIdx}}{{end}}"></span></td>
+			<td class="lines-num lines-num-old" data-line-num="{{if $line.LeftIdx}}{{$line.LeftIdx}}{{end}}"><span rel="{{if $line.LeftIdx}}diff-{{$.FileNameHash}}L{{$line.LeftIdx}}{{end}}"{{if $line.LeftIdx}} id="diff-{{$.FileNameHash}}L{{$line.LeftIdx}}"{{end}}></span></td>
 			<td class="lines-escape lines-escape-old">{{if and $line.LeftIdx $inlineDiff.EscapeStatus.Escaped}}<button class="toggle-escape-button btn interact-bg" title="{{template "repo/diff/escape_title" dict "diff" $inlineDiff}}"></button>{{end}}</td>
 			<td class="lines-type-marker lines-type-marker-old">{{if $line.LeftIdx}}<span class="tw-font-mono" data-type-marker=""></span>{{end}}</td>
 			<td class="lines-code lines-code-old">
@@ -27,7 +27,7 @@
 					<code class="code-inner"></code>
 				{{- end -}}
 			</td>
-			<td class="lines-num lines-num-new" data-line-num="{{if $line.RightIdx}}{{$line.RightIdx}}{{end}}"><span rel="{{if $line.RightIdx}}diff-{{$.FileNameHash}}R{{$line.RightIdx}}{{end}}"></span></td>
+			<td class="lines-num lines-num-new" data-line-num="{{if $line.RightIdx}}{{$line.RightIdx}}{{end}}"><span rel="{{if $line.RightIdx}}diff-{{$.FileNameHash}}R{{$line.RightIdx}}{{end}}"{{if $line.RightIdx}} id="diff-{{$.FileNameHash}}R{{$line.RightIdx}}"{{end}}></span></td>
 			<td class="lines-escape lines-escape-new">{{if and $line.RightIdx $inlineDiff.EscapeStatus.Escaped}}<button class="toggle-escape-button btn interact-bg" title="{{template "repo/diff/escape_title" dict "diff" $inlineDiff}}"></button>{{end}}</td>
 			<td class="lines-type-marker lines-type-marker-new">{{if $line.RightIdx}}<span class="tw-font-mono" data-type-marker=""></span>{{end}}</td>
 			<td class="lines-code lines-code-new">
@@ -65,8 +65,8 @@
 		{{if eq .GetType 4}}
 			<td colspan="2" class="lines-num">{{$line.RenderBlobExcerptButtons $.FileNameHash $diffBlobExcerptData}}</td>
 		{{else}}
-			<td class="lines-num lines-num-old" data-line-num="{{if $line.LeftIdx}}{{$line.LeftIdx}}{{end}}"><span rel="{{if $line.LeftIdx}}diff-{{$.FileNameHash}}L{{$line.LeftIdx}}{{end}}"></span></td>
+			<td class="lines-num lines-num-old" data-line-num="{{if $line.LeftIdx}}{{$line.LeftIdx}}{{end}}"><span rel="{{if $line.LeftIdx}}diff-{{$.FileNameHash}}L{{$line.LeftIdx}}{{end}}"{{if $line.LeftIdx}} id="diff-{{$.FileNameHash}}L{{$line.LeftIdx}}"{{end}}></span></td>
-			<td class="lines-num lines-num-new" data-line-num="{{if $line.RightIdx}}{{$line.RightIdx}}{{end}}"><span rel="{{if $line.RightIdx}}diff-{{$.FileNameHash}}R{{$line.RightIdx}}{{end}}"></span></td>
+			<td class="lines-num lines-num-new" data-line-num="{{if $line.RightIdx}}{{$line.RightIdx}}{{end}}"><span rel="{{if $line.RightIdx}}diff-{{$.FileNameHash}}R{{$line.RightIdx}}{{end}}"{{if $line.RightIdx}} id="diff-{{$.FileNameHash}}R{{$line.RightIdx}}"{{end}}></span></td>
 		{{end}}
 		{{$inlineDiff := $.section.GetComputedInlineDiffFor $line ctx.Locale}}
 		<td class="lines-escape">{{if $inlineDiff.EscapeStatus.Escaped}}<button class="toggle-escape-button btn interact-bg" title="{{template "repo/diff/escape_title" dict "diff" $inlineDiff}}"></button>{{end}}</td>

templates/repo/diff/section_split.tmpl

@@ -24,7 +24,7 @@
 					{{$match := index $section.Lines $line.Match}}
 					{{- $leftDiff := ""}}{{if $line.LeftIdx}}{{$leftDiff = $section.GetComputedInlineDiffFor $line ctx.Locale}}{{end}}
 					{{- $rightDiff := ""}}{{if $match.RightIdx}}{{$rightDiff = $section.GetComputedInlineDiffFor $match ctx.Locale}}{{end}}
-					<td class="lines-num lines-num-old del-code" data-line-num="{{$line.LeftIdx}}"><span rel="diff-{{$file.NameHash}}L{{$line.LeftIdx}}"></span></td>
+					<td class="lines-num lines-num-old del-code" data-line-num="{{$line.LeftIdx}}"><span rel="diff-{{$file.NameHash}}L{{$line.LeftIdx}}" id="diff-{{$file.NameHash}}L{{$line.LeftIdx}}"></span></td>
 					<td class="lines-escape del-code lines-escape-old">{{if $line.LeftIdx}}{{if $leftDiff.EscapeStatus.Escaped}}<button class="toggle-escape-button btn interact-bg" title="{{template "repo/diff/escape_title" dict "diff" $leftDiff}}"></button>{{end}}{{end}}</td>
 					<td class="lines-type-marker lines-type-marker-old del-code"><span class="tw-font-mono" data-type-marker="{{$line.GetLineTypeMarker}}"></span></td>
 					<td class="lines-code lines-code-old del-code">
@@ -39,7 +39,7 @@
 							<code class="code-inner"></code>
 						{{- end -}}
 					</td>
-					<td class="lines-num lines-num-new add-code" data-line-num="{{if $match.RightIdx}}{{$match.RightIdx}}{{end}}"><span rel="{{if $match.RightIdx}}diff-{{$file.NameHash}}R{{$match.RightIdx}}{{end}}"></span></td>
+					<td class="lines-num lines-num-new add-code" data-line-num="{{if $match.RightIdx}}{{$match.RightIdx}}{{end}}"><span rel="{{if $match.RightIdx}}diff-{{$file.NameHash}}R{{$match.RightIdx}}{{end}}"{{if $match.RightIdx}} id="diff-{{$file.NameHash}}R{{$match.RightIdx}}"{{end}}></span></td>
 					<td class="lines-escape add-code lines-escape-new">{{if $match.RightIdx}}{{if $rightDiff.EscapeStatus.Escaped}}<button class="toggle-escape-button btn interact-bg" title="{{template "repo/diff/escape_title" dict "diff" $rightDiff}}"></button>{{end}}{{end}}</td>
 					<td class="lines-type-marker lines-type-marker-new add-code">{{if $match.RightIdx}}<span class="tw-font-mono" data-type-marker="{{$match.GetLineTypeMarker}}"></span>{{end}}</td>
 					<td class="lines-code lines-code-new add-code">
@@ -56,7 +56,7 @@
 					</td>
 				{{else}}
 					{{$inlineDiff := $section.GetComputedInlineDiffFor $line ctx.Locale}}
-					<td class="lines-num lines-num-old" data-line-num="{{if $line.LeftIdx}}{{$line.LeftIdx}}{{end}}"><span rel="{{if $line.LeftIdx}}diff-{{$file.NameHash}}L{{$line.LeftIdx}}{{end}}"></span></td>
+					<td class="lines-num lines-num-old" data-line-num="{{if $line.LeftIdx}}{{$line.LeftIdx}}{{end}}"><span rel="{{if $line.LeftIdx}}diff-{{$file.NameHash}}L{{$line.LeftIdx}}{{end}}"{{if $line.LeftIdx}} id="diff-{{$file.NameHash}}L{{$line.LeftIdx}}"{{end}}></span></td>
 					<td class="lines-escape lines-escape-old">{{if $line.LeftIdx}}{{if $inlineDiff.EscapeStatus.Escaped}}<button class="toggle-escape-button btn interact-bg" title="{{template "repo/diff/escape_title" dict "diff" $inlineDiff}}"></button>{{end}}{{end}}</td>
 					<td class="lines-type-marker lines-type-marker-old">{{if $line.LeftIdx}}<span class="tw-font-mono" data-type-marker="{{$line.GetLineTypeMarker}}"></span>{{end}}</td>
 					<td class="lines-code lines-code-old">
@@ -71,7 +71,7 @@
 							<code class="code-inner"></code>
 						{{- end -}}
 					</td>
-					<td class="lines-num lines-num-new" data-line-num="{{if $line.RightIdx}}{{$line.RightIdx}}{{end}}"><span rel="{{if $line.RightIdx}}diff-{{$file.NameHash}}R{{$line.RightIdx}}{{end}}"></span></td>
+					<td class="lines-num lines-num-new" data-line-num="{{if $line.RightIdx}}{{$line.RightIdx}}{{end}}"><span rel="{{if $line.RightIdx}}diff-{{$file.NameHash}}R{{$line.RightIdx}}{{end}}"{{if $line.RightIdx}} id="diff-{{$file.NameHash}}R{{$line.RightIdx}}"{{end}}></span></td>
 					<td class="lines-escape lines-escape-new">{{if $line.RightIdx}}{{if $inlineDiff.EscapeStatus.Escaped}}<button class="toggle-escape-button btn interact-bg" title="{{template "repo/diff/escape_title" dict "diff" $inlineDiff}}"></button>{{end}}{{end}}</td>
 					<td class="lines-type-marker lines-type-marker-new">{{if $line.RightIdx}}<span class="tw-font-mono" data-type-marker="{{$line.GetLineTypeMarker}}"></span>{{end}}</td>
 					<td class="lines-code lines-code-new">

templates/repo/diff/section_unified.tmpl

@@ -19,8 +19,8 @@
 					<td colspan="2" class="lines-num"></td>
 				{{end}}
 			{{else}}
-				<td class="lines-num lines-num-old" data-line-num="{{if $line.LeftIdx}}{{$line.LeftIdx}}{{end}}"><span rel="{{if $line.LeftIdx}}diff-{{$file.NameHash}}L{{$line.LeftIdx}}{{end}}"></span></td>
+				<td class="lines-num lines-num-old" data-line-num="{{if $line.LeftIdx}}{{$line.LeftIdx}}{{end}}"><span rel="{{if $line.LeftIdx}}diff-{{$file.NameHash}}L{{$line.LeftIdx}}{{end}}"{{if $line.LeftIdx}} id="diff-{{$file.NameHash}}L{{$line.LeftIdx}}"{{end}}></span></td>
-				<td class="lines-num lines-num-new" data-line-num="{{if $line.RightIdx}}{{$line.RightIdx}}{{end}}"><span rel="{{if $line.RightIdx}}diff-{{$file.NameHash}}R{{$line.RightIdx}}{{end}}"></span></td>
+				<td class="lines-num lines-num-new" data-line-num="{{if $line.RightIdx}}{{$line.RightIdx}}{{end}}"><span rel="{{if $line.RightIdx}}diff-{{$file.NameHash}}R{{$line.RightIdx}}{{end}}"{{if $line.RightIdx}} id="diff-{{$file.NameHash}}R{{$line.RightIdx}}"{{end}}></span></td>
 			{{end}}
 			{{$inlineDiff := $section.GetComputedInlineDiffFor $line ctx.Locale -}}
 			<td class="lines-escape">

web_src/css/repo.css

@@ -986,6 +986,14 @@ td .commit-summary {
   text-align: right;
 }
 
+.repository .diff-file-box .code-diff .lines-num[data-line-num] {
+  cursor: pointer;
+}
+
+.repository .diff-file-box .code-diff .lines-num[data-line-num]:hover {
+  color: var(--color-text-dark);
+}
+
 .repository .diff-file-box .code-diff tbody tr .lines-type-marker {
   width: 10px;
   min-width: 10px;
@@ -997,6 +1005,32 @@ td .commit-summary {
   display: inline-block;
 }
 
+.repository .diff-file-box .code-diff tr.active .lines-num,
+.repository .diff-file-box .code-diff tr.active .lines-escape,
+.repository .diff-file-box .code-diff tr.active .lines-type-marker,
+.repository .diff-file-box .code-diff tr.active .lines-code {
+  background: var(--color-highlight-bg);
+}
+
+.repository .diff-file-box .code-diff tr.active .lines-num {
+  position: relative;
+}
+
+.repository .diff-file-box .code-diff tr.active .lines-num::after {
+  display: none;
+}
+
+.repository .diff-file-box .code-diff tr.active .lines-num:first-of-type::after {
+  content: "";
+  position: absolute;
+  left: 0;
+  top: 0;
+  bottom: 0;
+  width: 2px;
+  background: var(--color-highlight-fg);
+  display: block;
+}
+
 .repository .diff-file-box .code-diff-split .tag-code .lines-code code.code-inner {
   padding-left: 10px !important;
 }

web_src/js/features/repo-diff-selection.ts

@@ -0,0 +1,241 @@
+import {addDelegatedEventListener} from '../utils/dom.ts';
+import {sleep} from '../utils.ts';
+import {setFileFolding} from './file-fold.ts';
+
+const diffLineNumberCellSelector = '#diff-file-boxes .code-diff td.lines-num[data-line-num]';
+const diffAnchorSuffixRegex = /([LR])(\d+)$/;
+const diffHashRangeRegex = /^(diff-[0-9a-f]+)([LR]\d+)(?:-([LR]\d+))?$/i;
+
+type DiffAnchorSide = 'L' | 'R';
+type DiffAnchorInfo = {anchor: string, fragment: string, side: DiffAnchorSide, line: number};
+type DiffSelectionState = DiffAnchorInfo & {container: HTMLElement};
+type DiffSelectionRange = {fragment: string, startSide: DiffAnchorSide, startLine: number, endSide: DiffAnchorSide, endLine: number};
+
+let diffSelectionStart: DiffSelectionState | null = null;
+
+function changeHash(hash: string) {
+  if (window.history.pushState) {
+    window.history.pushState(null, null, hash);
+  } else {
+    window.location.hash = hash;
+  }
+}
+
+function parseDiffAnchor(anchor: string | null): DiffAnchorInfo | null {
+  if (!anchor || !anchor.startsWith('diff-')) return null;
+  const suffixMatch = diffAnchorSuffixRegex.exec(anchor);
+  if (!suffixMatch) return null;
+  const line = Number.parseInt(suffixMatch[2]);
+  if (Number.isNaN(line)) return null;
+  const fragment = anchor.slice(0, -suffixMatch[0].length);
+  const side = suffixMatch[1] as DiffAnchorSide;
+  return {anchor, fragment, side, line};
+}
+
+function applyDiffLineSelection(container: HTMLElement, range: DiffSelectionRange, options?: {updateHash?: boolean}): boolean {
+  // Find the start and end anchor elements
+  const startId = `${range.fragment}${range.startSide}${range.startLine}`;
+  const endId = `${range.fragment}${range.endSide}${range.endLine}`;
+  const startSpan = container.querySelector<HTMLElement>(`#${CSS.escape(startId)}`);
+  const endSpan = container.querySelector<HTMLElement>(`#${CSS.escape(endId)}`);
+
+  if (!startSpan || !endSpan) return false;
+
+  const startTr = startSpan.closest('tr');
+  const endTr = endSpan.closest('tr');
+  if (!startTr || !endTr) return false;
+
+  // Clear previous selection
+  for (const tr of document.querySelectorAll('.code-diff tr.active')) {
+    tr.classList.remove('active');
+  }
+
+  // Get all rows in the diff section
+  const allRows = Array.from(container.querySelectorAll<HTMLElement>('.code-diff tbody tr'));
+  const startIndex = allRows.indexOf(startTr);
+  const endIndex = allRows.indexOf(endTr);
+
+  if (startIndex === -1 || endIndex === -1) return false;
+
+  // Select all rows between start and end (inclusive)
+  const minIndex = Math.min(startIndex, endIndex);
+  const maxIndex = Math.max(startIndex, endIndex);
+
+  for (let i = minIndex; i <= maxIndex; i++) {
+    const row = allRows[i];
+    // Only select rows that are actual diff lines (not comment rows, expansion buttons, etc.)
+    // Skip rows with data-line-type="4" which are code expansion buttons
+    if (row.querySelector('td.lines-num') && row.getAttribute('data-line-type') !== '4') {
+      row.classList.add('active');
+    }
+  }
+
+  if (options?.updateHash !== false) {
+    const startAnchor = `${range.fragment}${range.startSide}${range.startLine}`;
+    const hashValue = (range.startSide === range.endSide && range.startLine === range.endLine) ?
+      startAnchor :
+      `${startAnchor}-${range.endSide}${range.endLine}`;
+    changeHash(`#${hashValue}`);
+  }
+  return true;
+}
+
+export function parseDiffHashRange(hashValue: string): DiffSelectionRange | null {
+  if (!hashValue.startsWith('diff-')) return null;
+  const match = diffHashRangeRegex.exec(hashValue);
+  if (!match) return null;
+  const startInfo = parseDiffAnchor(`${match[1]}${match[2]}`);
+  if (!startInfo) return null;
+  let endSide = startInfo.side;
+  let endLine = startInfo.line;
+  if (match[3]) {
+    const endInfo = parseDiffAnchor(`${match[1]}${match[3]}`);
+    if (!endInfo) {
+      return {fragment: startInfo.fragment, startSide: startInfo.side, startLine: startInfo.line, endSide: startInfo.side, endLine: startInfo.line};
+    }
+    endSide = endInfo.side;
+    endLine = endInfo.line;
+  }
+  return {
+    fragment: startInfo.fragment,
+    startSide: startInfo.side,
+    startLine: startInfo.line,
+    endSide,
+    endLine,
+  };
+}
+
+export async function highlightDiffSelectionFromHash(): Promise<boolean> {
+  const {hash} = window.location;
+  if (!hash || !hash.startsWith('#diff-')) return false;
+  const range = parseDiffHashRange(hash.substring(1));
+  if (!range) return false;
+  const targetId = `${range.fragment}${range.startSide}${range.startLine}`;
+
+  // Wait for the target element to be available (in case it needs to be loaded)
+  const targetSpan = document.querySelector<HTMLElement>(`#${CSS.escape(targetId)}`);
+  if (!targetSpan) {
+    // Target not found - it might need to be loaded via "show more files"
+    // Return false to let onLocationHashChange handle the loading
+    return false;
+  }
+
+  const container = targetSpan.closest<HTMLElement>('.diff-file-box');
+  if (!container) return false;
+
+  // Check if the file is collapsed and expand it if needed
+  if (container.getAttribute('data-folded') === 'true') {
+    const foldBtn = container.querySelector<HTMLElement>('.fold-file');
+    if (foldBtn) {
+      // Expand the file using the setFileFolding utility
+      setFileFolding(container, foldBtn, false);
+      // Wait a bit for the expansion animation
+      await sleep(100);
+    }
+  }
+
+  if (!applyDiffLineSelection(container, range, {updateHash: false})) return false;
+  diffSelectionStart = {
+    anchor: targetId,
+    fragment: range.fragment,
+    side: range.startSide,
+    line: range.startLine,
+    container,
+  };
+
+  // Scroll to the first selected line (scroll to the tr element, not the span)
+  // The span is an inline element inside td, we need to scroll to the tr for better visibility
+  await sleep(10);
+  const targetTr = targetSpan.closest('tr');
+  if (targetTr) {
+    targetTr.scrollIntoView({behavior: 'smooth', block: 'center'});
+  }
+  return true;
+}
+
+function handleDiffLineNumberClick(cell: HTMLElement, e: MouseEvent) {
+  let span = cell.querySelector<HTMLSpanElement>('span[id^="diff-"]');
+  let info = parseDiffAnchor(span?.id ?? null);
+
+  // If clicked cell has no line number (e.g., clicking on the empty side of a deletion/addition),
+  // try to find the line number from the sibling cell on the same row
+  if (!info) {
+    const row = cell.closest('tr');
+    if (!row) return;
+    // Find the other line number cell in the same row
+    const siblingCell = cell.classList.contains('lines-num-old') ?
+      row.querySelector<HTMLElement>('td.lines-num-new') :
+      row.querySelector<HTMLElement>('td.lines-num-old');
+    if (siblingCell) {
+      span = siblingCell.querySelector<HTMLSpanElement>('span[id^="diff-"]');
+      info = parseDiffAnchor(span?.id ?? null);
+    }
+    if (!info) return;
+  }
+
+  const container = cell.closest<HTMLElement>('.diff-file-box');
+  if (!container) return;
+
+  e.preventDefault();
+
+  // Check if clicking on a single already-selected line without shift key - deselect it
+  if (!e.shiftKey) {
+    const clickedRow = cell.closest('tr');
+    if (clickedRow?.classList.contains('active')) {
+      // Check if this is a single-line selection by checking if it's the only selected line
+      const selectedRows = container.querySelectorAll('.code-diff tr.active');
+      if (selectedRows.length === 1) {
+        // This is a single selected line, deselect it
+        clickedRow.classList.remove('active');
+        diffSelectionStart = null;
+        // Remove hash from URL completely
+        if (window.history.pushState) {
+          window.history.pushState(null, null, window.location.pathname + window.location.search);
+        } else {
+          window.location.hash = '';
+        }
+        window.getSelection().removeAllRanges();
+        return;
+      }
+    }
+  }
+
+  let rangeStart: DiffAnchorInfo = info;
+  if (e.shiftKey && diffSelectionStart &&
+    diffSelectionStart.container === container &&
+    diffSelectionStart.fragment === info.fragment) {
+    rangeStart = diffSelectionStart;
+  }
+
+  const range: DiffSelectionRange = {
+    fragment: info.fragment,
+    startSide: rangeStart.side,
+    startLine: rangeStart.line,
+    endSide: info.side,
+    endLine: info.line,
+  };
+
+  if (applyDiffLineSelection(container, range)) {
+    if (!e.shiftKey || !diffSelectionStart || diffSelectionStart.container !== container || diffSelectionStart.fragment !== info.fragment) {
+      diffSelectionStart = {...info, container};
+    }
+    window.getSelection().removeAllRanges();
+  }
+}
+
+export function initDiffLineSelection() {
+  addDelegatedEventListener<HTMLElement, MouseEvent>(document, 'click', diffLineNumberCellSelector, (cell, e) => {
+    if (e.defaultPrevented) return;
+    // Ignore clicks on or inside code-expander-buttons
+    const target = e.target as HTMLElement;
+    if (target.closest('.code-expander-button') || target.closest('.code-expander-buttons') ||
+      target.closest('button, a, input, select, textarea, summary, [role="button"]')) {
+      return;
+    }
+    handleDiffLineNumberClick(cell, e);
+  });
+  window.addEventListener('hashchange', () => {
+    highlightDiffSelectionFromHash();
+  });
+  highlightDiffSelectionFromHash();
+}

web_src/js/features/repo-diff.ts

@@ -11,6 +11,7 @@ import {createTippy} from '../modules/tippy.ts';
 import {invertFileFolding} from './file-fold.ts';
 import {parseDom, sleep} from '../utils.ts';
 import {registerGlobalSelectorFunc} from '../modules/observer.ts';
+import {parseDiffHashRange, highlightDiffSelectionFromHash, initDiffLineSelection} from './repo-diff-selection.ts';
 
 function initRepoDiffFileBox(el: HTMLElement) {
   // switch between "rendered" and "source", for image and CSV files
@@ -149,12 +150,14 @@ function initDiffHeaderPopup() {
 }
 
 // Will be called when the show more (files) button has been pressed
-function onShowMoreFiles() {
+async function onShowMoreFiles() {
   // TODO: replace these calls with the "observer.ts" methods
   initRepoIssueContentHistory();
   initViewedCheckboxListenerFor();
   initImageDiff();
   initDiffHeaderPopup();
+  // Re-apply hash selection in case the target was just loaded
+  await highlightDiffSelectionFromHash();
 }
 
 async function loadMoreFiles(btn: Element): Promise<boolean> {
@@ -225,20 +228,46 @@ async function onLocationHashChange() {
   const attrAutoScrollRunning = 'data-auto-scroll-running';
   if (document.body.hasAttribute(attrAutoScrollRunning)) return;
 
-  const targetElementId = currentHash.substring(1);
+  // Check if this is a diff line selection hash (e.g., #diff-xxxL10 or #diff-xxxL10-R20)
-  while (currentHash === window.location.hash) {
+  const hashValue = currentHash.substring(1);
-    // use getElementById to avoid querySelector throws an error when the hash is invalid
+  const range = parseDiffHashRange(hashValue);
-    // eslint-disable-next-line unicorn/prefer-query-selector
+  if (range) {
-    const targetElement = document.getElementById(targetElementId);
+    // This is a line selection hash, try to highlight it first
-    if (targetElement) {
+    const success = await highlightDiffSelectionFromHash();
-      // need to change hash to re-trigger ":target" CSS selector, let's manually scroll to it
+    if (success) {
-      targetElement.scrollIntoView();
+      // Successfully highlighted and scrolled, we're done
-      document.body.setAttribute(attrAutoScrollRunning, 'true');
-      window.location.hash = '';
-      window.location.hash = currentHash;
-      setTimeout(() => document.body.removeAttribute(attrAutoScrollRunning), 0);
       return;
     }
+    // If not successful, fall through to load more files
+  }
+
+  const targetElementId = hashValue;
+  while (currentHash === window.location.hash) {
+    // For line selections, check the range-based target
+    let targetElement;
+    if (range) {
+      const targetId = `${range.fragment}${range.startSide}${range.startLine}`;
+      // eslint-disable-next-line unicorn/prefer-query-selector
+      targetElement = document.getElementById(targetId);
+      if (targetElement) {
+        // Try again to highlight and scroll now that the element is loaded
+        await highlightDiffSelectionFromHash();
+        return;
+      }
+    } else {
+      // use getElementById to avoid querySelector throws an error when the hash is invalid
+      // eslint-disable-next-line unicorn/prefer-query-selector
+      targetElement = document.getElementById(targetElementId);
+      if (targetElement) {
+        // need to change hash to re-trigger ":target" CSS selector, let's manually scroll to it
+        targetElement.scrollIntoView();
+        document.body.setAttribute(attrAutoScrollRunning, 'true');
+        window.location.hash = '';
+        window.location.hash = currentHash;
+        setTimeout(() => document.body.removeAttribute(attrAutoScrollRunning), 0);
+        return;
+      }
+    }
 
     // If looking for a hidden comment, try to expand the section that contains it
     const issueCommentPrefix = '#issuecomment-';
@@ -284,6 +313,7 @@ export function initRepoDiffView() {
   initDiffHeaderPopup();
   initViewedCheckboxListenerFor();
   initExpandAndCollapseFilesButton();
+  initDiffLineSelection();
   initRepoDiffHashChangeListener();
 
   registerGlobalSelectorFunc('#diff-file-boxes .diff-file-box', initRepoDiffFileBox);