diff --git a/modules/markup/html.go b/modules/markup/html.go
index 0ac0463493..a7d882b00d 100644
--- a/modules/markup/html.go
+++ b/modules/markup/html.go
@@ -46,6 +46,9 @@ var (
 
 	// valid chars in encoded path and parameter: [-+~_%.a-zA-Z0-9/]
 
+	// httpSchemePattern matches https:// or http://
+	httpSchemePattern = regexp.MustCompile(`^https?://`)
+
 	// hashCurrentPattern matches string that represents a commit SHA, e.g. d8a994ef243349f321568f9e36d5c3f444b99cae
 	// Although SHA1 hashes are 40 chars long, SHA256 are 64, the regex matches the hash from 7 to 64 chars in length
 	// so that abbreviated hash links can be used as well. This matches git and GitHub usability.
@@ -72,7 +75,7 @@ var (
 	//   https://html.spec.whatwg.org/multipage/input.html#e-mail-state-(type%3Demail)
 	emailRegex = regexp.MustCompile("(?:\\s|^|\\(|\\[)([a-zA-Z0-9.!#$%&'*+\\/=?^_`{|}~-]+@[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\\.[a-zA-Z0-9]{2,}(?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)+)(?:\\s|$|\\)|\\]|;|,|\\?|!|\\.(\\s|$))")
 
-	// Fediverse handle regex (same as emailRegex but with additonal @ or !
+	// Fediverse handle regex (same as emailRegex but with additional @ or !
 	// at start)
 	fediRegex = regexp.MustCompile("(?:\\s|^|\\(|\\[)([@!]([a-zA-Z0-9.!#$%&'*+\\/=?^_`{|}~-]+)@([a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\\.[a-zA-Z0-9]{2,}(?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)+))(?:\\s|$|\\)|\\]|;|,|\\?|!|\\.(\\s|$))")
 
@@ -826,10 +829,7 @@ func pullReviewCommitPatternProcessor(ctx *RenderContext, node *html.Node) {
 
 		text := "!" + id + " (commit "
 
-		baseURLEnd := strings.Index(urlFull, repoSlug) + len(repoSlug)
-		if len(ctx.Links.Base) > 0 && !strings.HasPrefix(ctx.Links.Base, urlFull[:baseURLEnd]) {
-			text = repoSlug + "@" + text
-		}
+		optionalRepoSlugAndInstancePath(ctx, &text, urlFull, repoSlug)
 
 		aNode.AppendChild(&html.Node{
 			Type: html.TextNode,
@@ -1083,10 +1083,7 @@ func fullHashPatternProcessor(ctx *RenderContext, node *html.Node) {
 		// We need to figure out the base of the provided URL, which is up to and including the
 		// `<owner>/<repo>` slug.
 		// With that we can determine if it matches the current repo, or if the slug should be shown.
-		baseURLEnd := strings.Index(urlFull, repoSlug) + len(repoSlug)
-		if len(ctx.Links.Base) > 0 && !strings.HasPrefix(ctx.Links.Base, urlFull[:baseURLEnd]) {
-			text = repoSlug + "@" + text
-		}
+		optionalRepoSlugAndInstancePath(ctx, &text, urlFull, repoSlug)
 
 		// 3rd capture group matches an optional file path after the SHA
 		filePath := ""
@@ -1191,10 +1188,7 @@ func comparePatternProcessor(ctx *RenderContext, node *html.Node) {
 
 		text := text1 + textDots + text2
 
-		baseURLEnd := strings.Index(urlFull, repoSlug) + len(repoSlug)
-		if len(ctx.Links.Base) > 0 && !strings.HasPrefix(ctx.Links.Base, urlFull[:baseURLEnd]) {
-			text = repoSlug + "@" + text
-		}
+		optionalRepoSlugAndInstancePath(ctx, &text, urlFull, repoSlug)
 
 		extra := ""
 		if query != "" {
@@ -1525,3 +1519,27 @@ func createDescriptionLink(href, content string) *html.Node {
 	textNode.Parent = linkNode
 	return linkNode
 }
+
+// Adds an optional repo slug and optionally the instance domain and URL
+//
+// The repo slug is added if the link points to a different repo
+// The instance domain and sub-path is added if the link points to a different instance
+func optionalRepoSlugAndInstancePath(ctx *RenderContext, text *string, fullURL, slug string) {
+	if len(ctx.Links.Base) > 0 {
+		// The fullURL is the url to e.g. the commit. The slug is e.g. `forgejo/forgejo`.
+		// To retrieve the instance domain and sub-path we need to remove the repo slug
+		slugStart := strings.LastIndex(fullURL, slug)
+		targetInstance := fullURL[:slugStart]
+
+		// Check if the URL points to a different instance
+		if setting.AppURL != targetInstance {
+			// Remove the http scheme for displaying
+			targetInstance = httpSchemePattern.ReplaceAllString(targetInstance, "")
+
+			*text = targetInstance + slug + "@" + *text
+		} else if !strings.HasSuffix(strings.TrimSuffix(ctx.Links.Base, "/"), slug) {
+			// If it is a link to a different repo, but on the same instance only add the repo slug
+			*text = slug + "@" + *text
+		}
+	}
+}
diff --git a/modules/markup/html_internal_test.go b/modules/markup/html_internal_test.go
index 21572bdda3..264f31978d 100644
--- a/modules/markup/html_internal_test.go
+++ b/modules/markup/html_internal_test.go
@@ -12,6 +12,7 @@ import (
 
 	"forgejo.org/modules/git"
 	"forgejo.org/modules/setting"
+	"forgejo.org/modules/test"
 	"forgejo.org/modules/util"
 
 	"github.com/stretchr/testify/assert"
@@ -19,9 +20,10 @@ import (
 )
 
 const (
-	TestAppURL  = "http://localhost:3000/"
-	TestOrgRepo = "gogits/gogs"
-	TestRepoURL = TestAppURL + TestOrgRepo + "/"
+	TestAppURL              = "http://localhost:3000/"
+	TestOrgRepo             = "gogits/gogs"
+	TestRepoURLWithoutSlash = TestAppURL + TestOrgRepo
+	TestRepoURL             = TestAppURL + TestOrgRepo + "/"
 )
 
 // externalIssueLink an HTML link to an alphanumeric-style issue
@@ -107,7 +109,7 @@ func TestRender_IssueIndexPattern(t *testing.T) {
 }
 
 func TestRender_IssueIndexPattern2(t *testing.T) {
-	setting.AppURL = TestAppURL
+	defer test.MockVariableValue(&setting.AppURL, TestAppURL)()
 
 	// numeric: render inputs with valid mentions
 	test := func(s, expectedFmt, marker string, indices ...int) {
@@ -174,7 +176,7 @@ func TestRender_IssueIndexPattern2(t *testing.T) {
 }
 
 func TestRender_IssueIndexPattern3(t *testing.T) {
-	setting.AppURL = TestAppURL
+	defer test.MockVariableValue(&setting.AppURL, TestAppURL)()
 
 	// alphanumeric: render inputs without valid mentions
 	test := func(s string) {
@@ -202,7 +204,7 @@ func TestRender_IssueIndexPattern3(t *testing.T) {
 }
 
 func TestRender_IssueIndexPattern4(t *testing.T) {
-	setting.AppURL = TestAppURL
+	defer test.MockVariableValue(&setting.AppURL, TestAppURL)()
 
 	// alphanumeric: render inputs with valid mentions
 	test := func(s, expectedFmt string, names ...string) {
@@ -222,7 +224,7 @@ func TestRender_IssueIndexPattern4(t *testing.T) {
 }
 
 func TestRender_IssueIndexPattern5(t *testing.T) {
-	setting.AppURL = TestAppURL
+	defer test.MockVariableValue(&setting.AppURL, TestAppURL)()
 
 	// regexp: render inputs without valid mentions
 	test := func(s, expectedFmt, pattern string, ids, names []string) {
@@ -265,7 +267,7 @@ func TestRender_IssueIndexPattern5(t *testing.T) {
 }
 
 func TestRender_IssueIndexPattern_Document(t *testing.T) {
-	setting.AppURL = TestAppURL
+	defer test.MockVariableValue(&setting.AppURL, TestAppURL)()
 	metas := map[string]string{
 		"format": "https://someurl.com/{user}/{repo}/{index}",
 		"user":   "someUser",
@@ -301,9 +303,9 @@ func testRenderIssueIndexPattern(t *testing.T, input, expected string, ctx *Rend
 }
 
 func TestRender_AutoLink(t *testing.T) {
-	setting.AppURL = TestAppURL
+	defer test.MockVariableValue(&setting.AppURL, TestAppURL)()
 
-	test := func(input, expected, base string) {
+	assert := func(input, expected, base string) {
 		var buffer strings.Builder
 		err := PostProcess(&RenderContext{
 			Ctx: git.DefaultContext,
@@ -330,7 +332,7 @@ func TestRender_AutoLink(t *testing.T) {
 
 	t.Run("Issue", func(t *testing.T) {
 		// render valid issue URLs
-		test(util.URLJoin(TestRepoURL, "issues", "3333"),
+		assert(util.URLJoin(TestRepoURL, "issues", "3333"),
 			numericIssueLink(util.URLJoin(TestRepoURL, "issues"), "ref-issue", 3333, "#"),
 			TestRepoURL)
 	})
@@ -338,81 +340,90 @@ func TestRender_AutoLink(t *testing.T) {
 	t.Run("Commit", func(t *testing.T) {
 		// render valid commit URLs
 		tmp := util.URLJoin(TestRepoURL, "commit", "d8a994ef243349f321568f9e36d5c3f444b99cae")
-		test(tmp, "<a href=\""+tmp+"\" class=\"commit\"><code class=\"nohighlight\">d8a994ef24</code></a>", TestRepoURL)
-		test(tmp, "<a href=\""+tmp+"\" class=\"commit\"><code class=\"nohighlight\">"+TestOrgRepo+"@d8a994ef24</code></a>", "https://localhost/forgejo/forgejo")
-		test(
+		assert(tmp, "<a href=\""+tmp+"\" class=\"commit\"><code class=\"nohighlight\">d8a994ef24</code></a>", TestRepoURLWithoutSlash)
+		assert(tmp, "<a href=\""+tmp+"\" class=\"commit\"><code class=\"nohighlight\">"+TestOrgRepo+"@d8a994ef24</code></a>", "/forgejo/forgejo")
+		assert(
 			tmp+"#diff-2",
 			"<a href=\""+tmp+"#diff-2\" class=\"commit\"><code class=\"nohighlight\">d8a994ef24 (diff-2)</code></a>",
 			TestRepoURL,
 		)
-		test(
+		assert(
 			tmp+"#diff-953bb4f01b7c77fa18f0cd54211255051e647dbc",
 			"<a href=\""+tmp+"#diff-953bb4f01b7c77fa18f0cd54211255051e647dbc\" class=\"commit\"><code class=\"nohighlight\">d8a994ef24 (diff-953bb4f01b)</code></a>",
-			TestRepoURL,
+			TestRepoURLWithoutSlash,
 		)
 
 		// render other commit URLs
 		tmp = "https://external-link.gitea.io/go-gitea/gitea/commit/d8a994ef243349f321568f9e36d5c3f444b99cae#diff-2"
-		test(tmp, "<a href=\""+tmp+"\" class=\"commit\"><code class=\"nohighlight\">d8a994ef24 (diff-2)</code></a>", "https://external-link.gitea.io/go-gitea/gitea")
-		test(tmp, "<a href=\""+tmp+"\" class=\"commit\"><code class=\"nohighlight\">go-gitea/gitea@d8a994ef24 (diff-2)</code></a>", TestRepoURL)
+		assert(tmp, "<a href=\""+tmp+"\" class=\"commit\"><code class=\"nohighlight\">external-link.gitea.io/go-gitea/gitea@d8a994ef24 (diff-2)</code></a>", TestOrgRepo)
+		defer test.MockVariableValue(&setting.AppURL, "https://external-link.gitea.io/")()
+		assert(tmp, "<a href=\""+tmp+"\" class=\"commit\"><code class=\"nohighlight\">d8a994ef24 (diff-2)</code></a>", "https://external-link.gitea.io/go-gitea/gitea")
 
-		tmp = "http://localhost:3000/gogits/gogs/src/commit/190d9492934af498c3f669d6a2431dc5459e5b20"
-		test(tmp, "<a href=\""+tmp+"\" class=\"commit\"><code class=\"nohighlight\">190d949293</code></a>", "http://localhost:3000/gogits/gogs")
-		test(tmp, "<a href=\""+tmp+"\" class=\"commit\"><code class=\"nohighlight\">gogits/gogs@190d949293</code></a>", "https://external-link.gitea.io/go-gitea/gitea")
+		tmp = TestAppURL + "gogits/gogs/src/commit/190d9492934af498c3f669d6a2431dc5459e5b20"
+		assert(tmp, "<a href=\""+tmp+"\" class=\"commit\"><code class=\"nohighlight\">localhost:3000/gogits/gogs@190d949293</code></a>", "https://external-link.gitea.io/go-gitea/gitea")
+		defer test.MockVariableValue(&setting.AppURL, TestAppURL)()
+		assert(tmp, "<a href=\""+tmp+"\" class=\"commit\"><code class=\"nohighlight\">190d949293</code></a>", "http://localhost:3000/gogits/gogs")
 
 		tmp = "http://localhost:3000/sub/gogits/gogs/src/commit/190d9492934af498c3f669d6a2431dc5459e5b20"
-		test(tmp, "<a href=\""+tmp+"\" class=\"commit\"><code class=\"nohighlight\">190d949293</code></a>", "http://localhost:3000/sub/gogits/gogs")
-		test(tmp, "<a href=\""+tmp+"\" class=\"commit\"><code class=\"nohighlight\">gogits/gogs@190d949293</code></a>", "http://localhost:3000/gogits/gogs")
-		test(tmp, "<a href=\""+tmp+"\" class=\"commit\"><code class=\"nohighlight\">gogits/gogs@190d949293</code></a>", "https://external-link.gitea.io/go-gitea/gitea")
+		assert(tmp, "<a href=\""+tmp+"\" class=\"commit\"><code class=\"nohighlight\">localhost:3000/sub/gogits/gogs@190d949293</code></a>", TestRepoURLWithoutSlash)
+		assert(tmp, "<a href=\""+tmp+"\" class=\"commit\"><code class=\"nohighlight\">localhost:3000/sub/gogits/gogs@190d949293</code></a>", "https://external-link.gitea.io/go-gitea/gitea")
+		defer test.MockVariableValue(&setting.AppURL, TestAppURL+"sub/")()
+		assert(tmp, "<a href=\""+tmp+"\" class=\"commit\"><code class=\"nohighlight\">190d949293</code></a>", "http://localhost:3000/sub/gogits/gogs")
 
 		tmp = "http://localhost:3000/sub1/sub2/sub3/gogits/gogs/src/commit/190d9492934af498c3f669d6a2431dc5459e5b20"
-		test(tmp, "<a href=\""+tmp+"\" class=\"commit\"><code class=\"nohighlight\">190d949293</code></a>", "http://localhost:3000/sub1/sub2/sub3/gogits/gogs")
-		test(tmp, "<a href=\""+tmp+"\" class=\"commit\"><code class=\"nohighlight\">gogits/gogs@190d949293</code></a>", "http://localhost:3000/sub1/gogits/gogs")
-		test(tmp, "<a href=\""+tmp+"\" class=\"commit\"><code class=\"nohighlight\">gogits/gogs@190d949293</code></a>", "https://external-link.gitea.io/go-gitea/gitea")
+		defer test.MockVariableValue(&setting.AppURL, TestAppURL+"sub1/sub2/sub3/")()
+		assert(tmp, "<a href=\""+tmp+"\" class=\"commit\"><code class=\"nohighlight\">190d949293</code></a>", "http://localhost:3000/sub1/sub2/sub3/gogits/gogs")
+		defer test.MockVariableValue(&setting.AppURL, TestAppURL)()
+		assert(tmp, "<a href=\""+tmp+"\" class=\"commit\"><code class=\"nohighlight\">localhost:3000/sub1/sub2/sub3/gogits/gogs@190d949293</code></a>", "http://localhost:3000/sub1/gogits/gogs")
+		assert(tmp, "<a href=\""+tmp+"\" class=\"commit\"><code class=\"nohighlight\">localhost:3000/sub1/sub2/sub3/gogits/gogs@190d949293</code></a>", "https://external-link.gitea.io/go-gitea/gitea")
 
 		// if the repository happens to be named like one of the known app routes (e.g. `src`),
 		// we can parse the URL correctly, if there is no sub path
 		tmp = "http://localhost:3000/gogits/src/commit/190d9492934af498c3f669d6a2431dc5459e5b20"
-		test(tmp, "<a href=\""+tmp+"\" class=\"commit\"><code class=\"nohighlight\">gogits/src@190d949293</code></a>", TestRepoURL)
+		assert(tmp, "<a href=\""+tmp+"\" class=\"commit\"><code class=\"nohighlight\">gogits/src@190d949293</code></a>", TestRepoURL)
 		tmp = "http://localhost:3000/gogits/src/src/commit/190d9492934af498c3f669d6a2431dc5459e5b20"
-		test(tmp, "<a href=\""+tmp+"\" class=\"commit\"><code class=\"nohighlight\">gogits/src@190d949293</code></a>", TestRepoURL)
+		assert(tmp, "<a href=\""+tmp+"\" class=\"commit\"><code class=\"nohighlight\">gogits/src@190d949293</code></a>", TestRepoURL)
 		// but if there is a sub path, we cannot reliably distinguish the repo name from the app route
 		tmp = "http://localhost:3000/sub/gogits/src/commit/190d9492934af498c3f669d6a2431dc5459e5b20"
-		test(tmp, "<a href=\""+tmp+"\" class=\"commit\"><code class=\"nohighlight\">sub/gogits@190d949293</code></a>", TestRepoURL)
+		assert(tmp, "<a href=\""+tmp+"\" class=\"commit\"><code class=\"nohighlight\">sub/gogits@190d949293</code></a>", TestRepoURL)
 	})
 
 	t.Run("Compare", func(t *testing.T) {
 		tmp := util.URLJoin(TestRepoURL, "compare", "d8a994ef243349f321568f9e36d5c3f444b99cae..190d9492934af498c3f669d6a2431dc5459e5b20")
-		test(tmp, "<a href=\""+tmp+"\" class=\"compare\"><code class=\"nohighlight\">d8a994ef24..190d949293</code></a>", TestRepoURL)
-		test(tmp, "<a href=\""+tmp+"\" class=\"compare\"><code class=\"nohighlight\">"+TestOrgRepo+"@d8a994ef24..190d949293</code></a>", "https://localhost/forgejo/forgejo")
+		assert(tmp, "<a href=\""+tmp+"\" class=\"compare\"><code class=\"nohighlight\">d8a994ef24..190d949293</code></a>", TestRepoURL)
+		assert(tmp, "<a href=\""+tmp+"\" class=\"compare\"><code class=\"nohighlight\">"+TestOrgRepo+"@d8a994ef24..190d949293</code></a>", "https://localhost/forgejo/forgejo")
 
+		defer test.MockVariableValue(&setting.AppURL, TestAppURL+"sub/")()
 		tmp = "http://localhost:3000/sub/gogits/gogs/compare/190d9492934af498c3f669d6a2431dc5459e5b20..d8a994ef243349f321568f9e36d5c3f444b99cae"
-		test(tmp, "<a href=\""+tmp+"\" class=\"compare\"><code class=\"nohighlight\">190d949293..d8a994ef24</code></a>", "http://localhost:3000/sub/gogits/gogs")
-		test(tmp, "<a href=\""+tmp+"\" class=\"compare\"><code class=\"nohighlight\">gogits/gogs@190d949293..d8a994ef24</code></a>", "http://localhost:3000/gogits/gogs")
-		test(tmp, "<a href=\""+tmp+"\" class=\"compare\"><code class=\"nohighlight\">gogits/gogs@190d949293..d8a994ef24</code></a>", "https://external-link.gitea.io/go-gitea/gitea")
+		assert(tmp, "<a href=\""+tmp+"\" class=\"compare\"><code class=\"nohighlight\">190d949293..d8a994ef24</code></a>", "http://localhost:3000/sub/gogits/gogs")
+		assert(tmp, "<a href=\""+tmp+"\" class=\"compare\"><code class=\"nohighlight\">gogits/gogs@190d949293..d8a994ef24</code></a>", "http://localhost:3000/sub/gogits/gugs")
+		defer test.MockVariableValue(&setting.AppURL, "https://external-link.gitea.io/")()
+		assert(tmp, "<a href=\""+tmp+"\" class=\"compare\"><code class=\"nohighlight\">localhost:3000/sub/gogits/gogs@190d949293..d8a994ef24</code></a>", "https://external-link.gitea.io/go-gitea/gitea")
 
+		defer test.MockVariableValue(&setting.AppURL, TestAppURL+"sub1/sub2/sub3/")()
 		tmp = "http://localhost:3000/sub1/sub2/sub3/gogits/gogs/compare/190d9492934af498c3f669d6a2431dc5459e5b20..d8a994ef243349f321568f9e36d5c3f444b99cae"
-		test(tmp, "<a href=\""+tmp+"\" class=\"compare\"><code class=\"nohighlight\">190d949293..d8a994ef24</code></a>", "http://localhost:3000/sub1/sub2/sub3/gogits/gogs")
-		test(tmp, "<a href=\""+tmp+"\" class=\"compare\"><code class=\"nohighlight\">gogits/gogs@190d949293..d8a994ef24</code></a>", "http://localhost:3000/sub1/gogits/gogs")
-		test(tmp, "<a href=\""+tmp+"\" class=\"compare\"><code class=\"nohighlight\">gogits/gogs@190d949293..d8a994ef24</code></a>", "https://external-link.gitea.io/go-gitea/gitea")
+		assert(tmp, "<a href=\""+tmp+"\" class=\"compare\"><code class=\"nohighlight\">190d949293..d8a994ef24</code></a>", "http://localhost:3000/sub1/sub2/sub3/gogits/gogs")
+		assert(tmp, "<a href=\""+tmp+"\" class=\"compare\"><code class=\"nohighlight\">gogits/gogs@190d949293..d8a994ef24</code></a>", "/gogits/gous")
+		assert(tmp, "<a href=\""+tmp+"\" class=\"compare\"><code class=\"nohighlight\">gogits/gogs@190d949293..d8a994ef24</code></a>", "https://external-link.gitea.io/go-gitea/gitea")
 
 		tmp = "https://codeberg.org/forgejo/forgejo/compare/8bbac4c679bea930c74849c355a60ed3c52f8eb5...e2278e5a38187a1dc84dc41d583ec8b44e7257c1?files=options/locale/locale_fi-FI.ini"
-		test(tmp, "<a href=\""+tmp+"\" class=\"compare\"><code class=\"nohighlight\">8bbac4c679...e2278e5a38 (options/locale/locale_fi-FI.ini)</code></a>", "https://codeberg.org/forgejo/forgejo")
-		test(tmp, "<a href=\""+tmp+"\" class=\"compare\"><code class=\"nohighlight\">forgejo/forgejo@8bbac4c679...e2278e5a38 (options/locale/locale_fi-FI.ini)</code></a>", TestRepoURL)
-		test(tmp+".", "<a href=\""+tmp+"\" class=\"compare\"><code class=\"nohighlight\">forgejo/forgejo@8bbac4c679...e2278e5a38 (options/locale/locale_fi-FI.ini)</code></a>.", TestRepoURL)
+		assert(tmp, "<a href=\""+tmp+"\" class=\"compare\"><code class=\"nohighlight\">codeberg.org/forgejo/forgejo@8bbac4c679...e2278e5a38 (options/locale/locale_fi-FI.ini)</code></a>", TestRepoURL)
+		assert(tmp+".", "<a href=\""+tmp+"\" class=\"compare\"><code class=\"nohighlight\">codeberg.org/forgejo/forgejo@8bbac4c679...e2278e5a38 (options/locale/locale_fi-FI.ini)</code></a>.", TestRepoURL)
+		defer test.MockVariableValue(&setting.AppURL, "https://codeberg.org/")()
+		assert(tmp, "<a href=\""+tmp+"\" class=\"compare\"><code class=\"nohighlight\">8bbac4c679...e2278e5a38 (options/locale/locale_fi-FI.ini)</code></a>", "https://codeberg.org/forgejo/forgejo")
 
 		tmp = "https://codeberg.org/forgejo/forgejo/compare/8bbac4c679bea930c74849c355a60ed3c52f8eb5...e2278e5a38187a1dc84dc41d583ec8b44e7257c1?files=options/locale/locale_fi-FI.ini#L2"
-		test(tmp, "<a href=\""+tmp+"\" class=\"compare\"><code class=\"nohighlight\">8bbac4c679...e2278e5a38 (options/locale/locale_fi-FI.ini#L2)</code></a>", "https://codeberg.org/forgejo/forgejo")
+		assert(tmp, "<a href=\""+tmp+"\" class=\"compare\"><code class=\"nohighlight\">8bbac4c679...e2278e5a38 (options/locale/locale_fi-FI.ini#L2)</code></a>", "https://codeberg.org/forgejo/forgejo")
 	})
 
 	t.Run("Invalid URLs", func(t *testing.T) {
 		tmp := "https://local host/gogits/src/commit/190d9492934af498c3f669d6a2431dc5459e5b20"
-		test(tmp, "<a href=\"https://local\" class=\"link\">https://local</a> host/gogits/src/commit/190d9492934af498c3f669d6a2431dc5459e5b20", TestRepoURL)
+		assert(tmp, "<a href=\"https://local\" class=\"link\">https://local</a> host/gogits/src/commit/190d9492934af498c3f669d6a2431dc5459e5b20", TestRepoURL)
 	})
 }
 
 func TestRender_IssueIndexPatternRef(t *testing.T) {
-	setting.AppURL = TestAppURL
+	defer test.MockVariableValue(&setting.AppURL, TestAppURL)()
 
 	test := func(input, expected string) {
 		var buf strings.Builder
@@ -428,7 +439,7 @@ func TestRender_IssueIndexPatternRef(t *testing.T) {
 }
 
 func TestRender_FullIssueURLs(t *testing.T) {
-	setting.AppURL = TestAppURL
+	defer test.MockVariableValue(&setting.AppURL, TestAppURL)()
 
 	test := func(input, expected string) {
 		var result strings.Builder
diff --git a/modules/markup/html_test.go b/modules/markup/html_test.go
index 6c6658748a..2ff829e627 100644
--- a/modules/markup/html_test.go
+++ b/modules/markup/html_test.go
@@ -41,7 +41,7 @@ func TestMain(m *testing.M) {
 }
 
 func TestRender_Commits(t *testing.T) {
-	setting.AppURL = markup.TestAppURL
+	defer test.MockVariableValue(&setting.AppURL, markup.TestAppURL)()
 	test := func(input, expected string) {
 		buffer, err := markup.RenderString(&markup.RenderContext{
 			Ctx:          git.DefaultContext,
@@ -98,10 +98,19 @@ func TestRender_Commits(t *testing.T) {
 
 	fileStrangeChars := util.URLJoin(repo, "src", "commit", "eeb243c3395e1921c5d90e73bd739827251fc99d", "path", "to", "file%20%23.txt")
 	test(fileStrangeChars, `<p><a href="`+fileStrangeChars+`" rel="nofollow"><code>eeb243c339/path/to/file #.txt</code></a></p>`)
+
+	commitLink := util.URLJoin(repo, "src", "commit", "eeb243c3395e1921c5d90e73bd739827251fc99d")
+	test(commitLink, `<p><a href="`+commitLink+`" rel="nofollow"><code>eeb243c339</code></a></p>`)
+
+	crossCommitLink := util.URLJoin(markup.TestAppURL, "forgejo/forgejo", "src", "commit", "eeb243c3395e1921c5d90e73bd739827251fc99d")
+	test(crossCommitLink, `<p><a href="`+crossCommitLink+`" rel="nofollow"><code>forgejo/forgejo@eeb243c339</code></a></p>`)
+
+	extCommitLink := util.URLJoin("https://codeberg.org/", markup.TestOrgRepo, "src", "commit", "eeb243c3395e1921c5d90e73bd739827251fc99d")
+	test(extCommitLink, `<p><a href="`+extCommitLink+`" rel="nofollow"><code>codeberg.org/`+markup.TestOrgRepo+`@eeb243c339</code></a></p>`)
 }
 
 func TestRender_CrossReferences(t *testing.T) {
-	setting.AppURL = markup.TestAppURL
+	defer test.MockVariableValue(&setting.AppURL, markup.TestAppURL)()
 
 	test := func(input, expected string) {
 		buffer, err := markup.RenderString(&markup.RenderContext{
@@ -144,7 +153,7 @@ func TestRender_CrossReferences(t *testing.T) {
 }
 
 func TestRender_links(t *testing.T) {
-	setting.AppURL = markup.TestAppURL
+	defer test.MockVariableValue(&setting.AppURL, markup.TestAppURL)()
 
 	test := func(input, expected string) {
 		buffer, err := markup.RenderString(&markup.RenderContext{
@@ -246,12 +255,12 @@ func TestRender_links(t *testing.T) {
 }
 
 func TestRender_PullReviewCommitLink(t *testing.T) {
-	setting.AppURL = markup.TestAppURL
+	defer test.MockVariableValue(&setting.AppURL, markup.TestAppURL)()
 
 	sha := "190d9492934af498c3f669d6a2431dc5459e5b20"
 	prCommitLink := util.URLJoin(markup.TestRepoURL, "pulls", "1", "commits", sha)
 
-	test := func(input, expected, base string) {
+	assert := func(input, expected, base string) {
 		buffer, err := markup.RenderString(&markup.RenderContext{
 			Ctx:          git.DefaultContext,
 			RelativePath: ".md",
@@ -265,27 +274,28 @@ func TestRender_PullReviewCommitLink(t *testing.T) {
 		assert.Equal(t, strings.TrimSpace(expected), strings.TrimSpace(buffer))
 	}
 
-	test(prCommitLink, `<p><a href="`+prCommitLink+`" rel="nofollow">!1 (commit <code>`+sha[0:10]+`</code>)</a></p>`, markup.TestRepoURL)
+	assert(prCommitLink, `<p><a href="`+prCommitLink+`" rel="nofollow">!1 (commit <code>`+sha[0:10]+`</code>)</a></p>`, markup.TestRepoURL)
 
 	prCommitLink = util.URLJoin(markup.TestAppURL, "sub1", "sub2", markup.TestOrgRepo, "pulls", "1", "commits", sha)
-	test(
+	assert(
 		prCommitLink,
-		`<p><a href="`+prCommitLink+`" rel="nofollow">!1 (commit <code>`+sha[0:10]+`</code>)</a></p>`,
+		`<p><a href="`+prCommitLink+`" rel="nofollow">localhost:3000/sub1/sub2/gogits/gogs@!1 (commit <code>`+sha[0:10]+`</code>)</a></p>`,
 		util.URLJoin(markup.TestAppURL, "sub1", "sub2", markup.TestOrgRepo),
 	)
-	test(
+	assert(
 		prCommitLink,
-		`<p><a href="`+prCommitLink+`" rel="nofollow">`+markup.TestOrgRepo+`@!1 (commit <code>`+sha[0:10]+`</code>)</a></p>`,
+		`<p><a href="`+prCommitLink+`" rel="nofollow">localhost:3000/sub1/sub2/gogits/gogs@!1 (commit <code>`+sha[0:10]+`</code>)</a></p>`,
 		markup.TestRepoURL,
 	)
 
 	prCommitLink = "https://codeberg.org/forgejo/forgejo/pulls/7979/commits/4d968c08e0a8d24bd2f3fb2a3a48b37e6d84a327#diff-7649acfa98a9ee3faf0d28b488bbff428317fc72"
-	test(prCommitLink, `<p><a href="`+prCommitLink+`" rel="nofollow">!7979 (commit <code>4d968c08e0</code>)</a></p>`, "https://codeberg.org/forgejo/forgejo")
-	test(prCommitLink, `<p><a href="`+prCommitLink+`" rel="nofollow">forgejo/forgejo@!7979 (commit <code>4d968c08e0</code>)</a></p>`, markup.TestRepoURL)
+	assert(prCommitLink, `<p><a href="`+prCommitLink+`" rel="nofollow">codeberg.org/forgejo/forgejo@!7979 (commit <code>4d968c08e0</code>)</a></p>`, markup.TestRepoURL)
+	defer test.MockVariableValue(&setting.AppURL, "https://codeberg.org/")()
+	assert(prCommitLink, `<p><a href="`+prCommitLink+`" rel="nofollow">!7979 (commit <code>4d968c08e0</code>)</a></p>`, "https://codeberg.org/forgejo/forgejo")
 }
 
 func TestRender_email(t *testing.T) {
-	setting.AppURL = markup.TestAppURL
+	defer test.MockVariableValue(&setting.AppURL, markup.TestAppURL)()
 
 	test := func(input, expected string) {
 		res, err := markup.RenderString(&markup.RenderContext{
@@ -369,7 +379,7 @@ func TestRender_email(t *testing.T) {
 }
 
 func TestRender_emoji(t *testing.T) {
-	setting.AppURL = markup.TestAppURL
+	defer test.MockVariableValue(&setting.AppURL, markup.TestAppURL)()
 	setting.StaticURLPrefix = markup.TestAppURL
 
 	test := func(input, expected string) {
@@ -436,7 +446,7 @@ func TestRender_emoji(t *testing.T) {
 }
 
 func TestRender_ShortLinks(t *testing.T) {
-	setting.AppURL = markup.TestAppURL
+	defer test.MockVariableValue(&setting.AppURL, markup.TestAppURL)()
 	tree := util.URLJoin(markup.TestRepoURL, "src", "master")
 
 	test := func(input, expected, expectedWiki string) {
@@ -549,7 +559,7 @@ func TestRender_ShortLinks(t *testing.T) {
 }
 
 func TestRender_RelativeImages(t *testing.T) {
-	setting.AppURL = markup.TestAppURL
+	defer test.MockVariableValue(&setting.AppURL, markup.TestAppURL)()
 
 	test := func(input, expected, expectedWiki string) {
 		buffer, err := markdown.RenderString(&markup.RenderContext{
@@ -589,7 +599,7 @@ func TestRender_RelativeImages(t *testing.T) {
 }
 
 func Test_ParseClusterFuzz(t *testing.T) {
-	setting.AppURL = markup.TestAppURL
+	defer test.MockVariableValue(&setting.AppURL, markup.TestAppURL)()
 
 	localMetas := map[string]string{
 		"user": "go-gitea",
@@ -625,7 +635,7 @@ func Test_ParseClusterFuzz(t *testing.T) {
 }
 
 func TestPostProcess_RenderDocument(t *testing.T) {
-	setting.AppURL = markup.TestAppURL
+	defer test.MockVariableValue(&setting.AppURL, markup.TestAppURL)()
 	setting.StaticURLPrefix = markup.TestAppURL // can't run standalone
 
 	localMetas := map[string]string{
@@ -670,7 +680,7 @@ func TestPostProcess_RenderDocument(t *testing.T) {
 }
 
 func TestIssue16020(t *testing.T) {
-	setting.AppURL = markup.TestAppURL
+	defer test.MockVariableValue(&setting.AppURL, markup.TestAppURL)()
 
 	localMetas := map[string]string{
 		"user": "go-gitea",
@@ -735,7 +745,7 @@ func TestIssue18471(t *testing.T) {
 	}, strings.NewReader(data), &res)
 
 	require.NoError(t, err)
-	assert.Equal(t, "<a href=\"http://domain/org/repo/compare/783b039...da951ce\" class=\"compare\"><code class=\"nohighlight\">783b039...da951ce</code></a>", res.String())
+	assert.Equal(t, "<a href=\"http://domain/org/repo/compare/783b039...da951ce\" class=\"compare\"><code class=\"nohighlight\">domain/org/repo@783b039...da951ce</code></a>", res.String())
 }
 
 func TestRender_FilePreview(t *testing.T) {
@@ -744,7 +754,7 @@ func TestRender_FilePreview(t *testing.T) {
 	defer test.MockVariableValue(&setting.Langs, []string{"en-US"})()
 	translation.InitLocales(t.Context())
 
-	setting.AppURL = markup.TestAppURL
+	defer test.MockVariableValue(&setting.AppURL, markup.TestAppURL)()
 	markup.Init(&markup.ProcessorHelper{
 		GetRepoFileBlob: func(ctx context.Context, ownerName, repoName, commitSha, filePath string, language *string) (*git.Blob, error) {
 			gitRepo, err := git.OpenRepository(git.DefaultContext, "./tests/repo/repo1_filepreview")
@@ -884,7 +894,7 @@ func TestRender_FilePreview(t *testing.T) {
 
 		testRender(
 			urlWithSub,
-			`<p><a href="http://localhost:3000/sub/gogits/gogs/src/commit/190d9492934af498c3f669d6a2431dc5459e5b20/path/to/file.go#L2-L3" rel="nofollow"><code>gogits/gogs@190d949293/path/to/file.go (L2-L3)</code></a></p>`,
+			`<p><a href="http://localhost:3000/sub/gogits/gogs/src/commit/190d9492934af498c3f669d6a2431dc5459e5b20/path/to/file.go#L2-L3" rel="nofollow"><code>localhost:3000/sub/gogits/gogs@190d949293/path/to/file.go (L2-L3)</code></a></p>`,
 			localMetas,
 		)
 
@@ -924,7 +934,7 @@ func TestRender_FilePreview(t *testing.T) {
 
 		testRender(
 			"first without sub "+commitFilePreview+" second "+urlWithSub,
-			`<p>first without sub <a href="http://localhost:3000/gogits/gogs/src/commit/190d9492934af498c3f669d6a2431dc5459e5b20/path/to/file.go#L2-L3" rel="nofollow"><code>190d949293/path/to/file.go (L2-L3)</code></a> second </p>`+
+			`<p>first without sub <a href="http://localhost:3000/gogits/gogs/src/commit/190d9492934af498c3f669d6a2431dc5459e5b20/path/to/file.go#L2-L3" rel="nofollow"><code>localhost:3000/gogits/gogs@190d949293/path/to/file.go (L2-L3)</code></a> second </p>`+
 				`<div class="file-preview-box">`+
 				`<div class="header">`+
 				`<div>`+