Fix panic where now a third link breaks everything

modules/markup/html.go

@@ -1086,7 +1086,8 @@ func filePreviewPatternProcessor(ctx *RenderContext, node *html.Node) {
 			// Specialized version of replaceContent, so the parent paragraph element is not destroyed from our div
 			before := node.Data[:(preview.start - offset)]
 			after := node.Data[(preview.end - offset):]
-			offset += preview.end - 3
+			afterPrefix := "<p>"
+			offset = preview.end - len(afterPrefix)
 			node.Data = before
 			nextSibling := node.NextSibling
 			node.Parent.InsertBefore(&html.Node{
@@ -1096,7 +1097,7 @@ func filePreviewPatternProcessor(ctx *RenderContext, node *html.Node) {
 			node.Parent.InsertBefore(previewNode, nextSibling)
 			afterNode := &html.Node{
 				Type: html.RawNode,
-				Data: "<p>" + after,
+				Data: afterPrefix + after,
 			}
 			node.Parent.InsertBefore(afterNode, nextSibling)
 			node = afterNode

modules/markup/html_test.go

@@ -917,5 +917,86 @@ func TestRender_FilePreview(t *testing.T) {
 				`<p></p>`,
 			localMetas,
 		)
+
+		testRender(
+			"first "+commitFilePreview+" second "+commitFilePreview+" third "+commitFilePreview,
+			`<p>first </p>`+
+				`<div class="file-preview-box">`+
+				`<div class="header">`+
+				`<div>`+
+				`<a href="http://localhost:3000/gogits/gogs/src/commit/190d9492934af498c3f669d6a2431dc5459e5b20/path/to/file.go#L2-L3" class="muted" rel="nofollow">path/to/file.go</a>`+
+				`</div>`+
+				`<span class="text small grey">`+
+				`Lines 2 to 3 in <a href="http://localhost:3000/gogits/gogs/src/commit/190d9492934af498c3f669d6a2431dc5459e5b20" class="text black" rel="nofollow">190d949</a>`+
+				`</span>`+
+				`</div>`+
+				`<div class="ui table">`+
+				`<table class="file-preview">`+
+				`<tbody>`+
+				`<tr>`+
+				`<td class="lines-num"><span data-line-number="2"></span></td>`+
+				`<td class="lines-code chroma"><code class="code-inner"><span class="nx">B</span>`+"\n"+`</code></td>`+
+				`</tr>`+
+				`<tr>`+
+				`<td class="lines-num"><span data-line-number="3"></span></td>`+
+				`<td class="lines-code chroma"><code class="code-inner"><span class="nx">C</span>`+"\n"+`</code></td>`+
+				`</tr>`+
+				`</tbody>`+
+				`</table>`+
+				`</div>`+
+				`</div>`+
+				`<p> second </p>`+
+				`<div class="file-preview-box">`+
+				`<div class="header">`+
+				`<div>`+
+				`<a href="http://localhost:3000/gogits/gogs/src/commit/190d9492934af498c3f669d6a2431dc5459e5b20/path/to/file.go#L2-L3" class="muted" rel="nofollow">path/to/file.go</a>`+
+				`</div>`+
+				`<span class="text small grey">`+
+				`Lines 2 to 3 in <a href="http://localhost:3000/gogits/gogs/src/commit/190d9492934af498c3f669d6a2431dc5459e5b20" class="text black" rel="nofollow">190d949</a>`+
+				`</span>`+
+				`</div>`+
+				`<div class="ui table">`+
+				`<table class="file-preview">`+
+				`<tbody>`+
+				`<tr>`+
+				`<td class="lines-num"><span data-line-number="2"></span></td>`+
+				`<td class="lines-code chroma"><code class="code-inner"><span class="nx">B</span>`+"\n"+`</code></td>`+
+				`</tr>`+
+				`<tr>`+
+				`<td class="lines-num"><span data-line-number="3"></span></td>`+
+				`<td class="lines-code chroma"><code class="code-inner"><span class="nx">C</span>`+"\n"+`</code></td>`+
+				`</tr>`+
+				`</tbody>`+
+				`</table>`+
+				`</div>`+
+				`</div>`+
+				`<p> third </p>`+
+				`<div class="file-preview-box">`+
+				`<div class="header">`+
+				`<div>`+
+				`<a href="http://localhost:3000/gogits/gogs/src/commit/190d9492934af498c3f669d6a2431dc5459e5b20/path/to/file.go#L2-L3" class="muted" rel="nofollow">path/to/file.go</a>`+
+				`</div>`+
+				`<span class="text small grey">`+
+				`Lines 2 to 3 in <a href="http://localhost:3000/gogits/gogs/src/commit/190d9492934af498c3f669d6a2431dc5459e5b20" class="text black" rel="nofollow">190d949</a>`+
+				`</span>`+
+				`</div>`+
+				`<div class="ui table">`+
+				`<table class="file-preview">`+
+				`<tbody>`+
+				`<tr>`+
+				`<td class="lines-num"><span data-line-number="2"></span></td>`+
+				`<td class="lines-code chroma"><code class="code-inner"><span class="nx">B</span>`+"\n"+`</code></td>`+
+				`</tr>`+
+				`<tr>`+
+				`<td class="lines-num"><span data-line-number="3"></span></td>`+
+				`<td class="lines-code chroma"><code class="code-inner"><span class="nx">C</span>`+"\n"+`</code></td>`+
+				`</tr>`+
+				`</tbody>`+
+				`</table>`+
+				`</div>`+
+				`</div>`+
+				`<p></p>`,
+			localMetas,
+		)
 	})
 }