Rework markup link rendering (#26745) (#28803)

Backport #26745
Fixes #26548

This PR refactors the rendering of markup links. The old code uses
`strings.Replace` to change some urls while the new code uses more
context to decide which link should be generated.

The added tests should ensure the same output for the old and new
behaviour (besides the bug).

We may need to refactor the rendering a bit more to make it clear how
the different helper methods render the input string. There are lots of
options (resolve links / images / mentions / git hashes / emojis / ...)
but you don't really know what helper uses which options. For example,
we currently support images in the user description which should not be
allowed I think:

<details>
  <summary>Profile</summary>

https://try.gitea.io/KN4CK3R


![grafik](https://github.com/go-gitea/gitea/assets/1666336/109ae422-496d-4200-b52e-b3a528f553e5)

</details>

1 files changed, 400 insertions, 22 deletions

diff --git a/modules/markup/markdown/markdown_test.go b/modules/markup/markdown/markdown_test.go
index f2322b2554..6f2bbae6e0 100644
--- a/modules/markup/markdown/markdown_test.go
+++ b/modules/markup/markdown/markdown_test.go
@@ -52,16 +52,20 @@ func TestRender_StandardLinks(t *testing.T) {
 
 	test := func(input, expected, expectedWiki string) {
 		buffer, err := RenderString(&markup.RenderContext{
-			Ctx:       git.DefaultContext,
-			URLPrefix: setting.AppSubURL,
+			Ctx: git.DefaultContext,
+			Links: markup.Links{
+				Base: setting.AppSubURL,
+			},
 		}, input)
 		assert.NoError(t, err)
 		assert.Equal(t, strings.TrimSpace(expected), strings.TrimSpace(buffer))
 
 		buffer, err = RenderString(&markup.RenderContext{
-			Ctx:       git.DefaultContext,
-			URLPrefix: setting.AppSubURL,
-			IsWiki:    true,
+			Ctx: git.DefaultContext,
+			Links: markup.Links{
+				Base: setting.AppSubURL,
+			},
+			IsWiki: true,
 		}, input)
 		assert.NoError(t, err)
 		assert.Equal(t, strings.TrimSpace(expectedWiki), strings.TrimSpace(buffer))
@@ -83,8 +87,10 @@ func TestRender_Images(t *testing.T) {
 
 	test := func(input, expected string) {
 		buffer, err := RenderString(&markup.RenderContext{
-			Ctx:       git.DefaultContext,
-			URLPrefix: setting.AppSubURL,
+			Ctx: git.DefaultContext,
+			Links: markup.Links{
+				Base: setting.AppSubURL,
+			},
 		}, input)
 		assert.NoError(t, err)
 		assert.Equal(t, strings.TrimSpace(expected), strings.TrimSpace(buffer))
@@ -107,7 +113,6 @@ func TestRender_Images(t *testing.T) {
 		"[!["+title+"]("+url+")]("+href+")",
 		`<p><a href="`+href+`" rel="nofollow"><img src="`+result+`" alt="`+title+`"/></a></p>`)
 
-	url = "/../../.images/src/02/train.jpg"
 	test(
 		"!["+title+"]("+url+")",
 		`<p><a href="`+result+`" target="_blank" rel="nofollow noopener"><img src="`+result+`" alt="`+title+`"/></a></p>`)
@@ -286,14 +291,16 @@ func TestTotal_RenderWiki(t *testing.T) {
 	setting.AppURL = AppURL
 	setting.AppSubURL = AppSubURL
 
-	answers := testAnswers(util.URLJoin(AppSubURL, "wiki/"), util.URLJoin(AppSubURL, "wiki", "raw/"))
+	answers := testAnswers(util.URLJoin(AppSubURL, "wiki"), util.URLJoin(AppSubURL, "wiki", "raw"))
 
 	for i := 0; i < len(sameCases); i++ {
 		line, err := RenderString(&markup.RenderContext{
-			Ctx:       git.DefaultContext,
-			URLPrefix: AppSubURL,
-			Metas:     localMetas,
-			IsWiki:    true,
+			Ctx: git.DefaultContext,
+			Links: markup.Links{
+				Base: setting.AppSubURL,
+			},
+			Metas:  localMetas,
+			IsWiki: true,
 		}, sameCases[i])
 		assert.NoError(t, err)
 		assert.Equal(t, answers[i], line)
@@ -314,9 +321,11 @@ func TestTotal_RenderWiki(t *testing.T) {
 
 	for i := 0; i < len(testCases); i += 2 {
 		line, err := RenderString(&markup.RenderContext{
-			Ctx:       git.DefaultContext,
-			URLPrefix: AppSubURL,
-			IsWiki:    true,
+			Ctx: git.DefaultContext,
+			Links: markup.Links{
+				Base: setting.AppSubURL,
+			},
+			IsWiki: true,
 		}, testCases[i])
 		assert.NoError(t, err)
 		assert.Equal(t, testCases[i+1], line)
@@ -327,13 +336,16 @@ func TestTotal_RenderString(t *testing.T) {
 	setting.AppURL = AppURL
 	setting.AppSubURL = AppSubURL
 
-	answers := testAnswers(util.URLJoin(AppSubURL, "src", "master/"), util.URLJoin(AppSubURL, "raw", "master/"))
+	answers := testAnswers(util.URLJoin(AppSubURL, "src", "master"), util.URLJoin(AppSubURL, "media", "master"))
 
 	for i := 0; i < len(sameCases); i++ {
 		line, err := RenderString(&markup.RenderContext{
-			Ctx:       git.DefaultContext,
-			URLPrefix: util.URLJoin(AppSubURL, "src", "master/"),
-			Metas:     localMetas,
+			Ctx: git.DefaultContext,
+			Links: markup.Links{
+				Base:       AppSubURL,
+				BranchPath: "master",
+			},
+			Metas: localMetas,
 		}, sameCases[i])
 		assert.NoError(t, err)
 		assert.Equal(t, answers[i], line)
@@ -343,8 +355,10 @@ func TestTotal_RenderString(t *testing.T) {
 
 	for i := 0; i < len(testCases); i += 2 {
 		line, err := RenderString(&markup.RenderContext{
-			Ctx:       git.DefaultContext,
-			URLPrefix: AppSubURL,
+			Ctx: git.DefaultContext,
+			Links: markup.Links{
+				Base: AppSubURL,
+			},
 		}, testCases[i])
 		assert.NoError(t, err)
 		assert.Equal(t, testCases[i+1], line)
@@ -556,3 +570,367 @@ foo: bar
 		assert.Equal(t, test.expected, res, "Unexpected result in testcase %q", test.testcase)
 	}
 }
+
+func TestRenderLinks(t *testing.T) {
+	input := `  space @mention-user  
+/just/a/path.bin
+https://example.com/file.bin
+[local link](file.bin)
+[remote link](https://example.com)
+[[local link|file.bin]]
+[[remote link|https://example.com]]
+![local image](image.jpg)
+![remote image](https://example.com/image.jpg)
+[[local image|image.jpg]]
+[[remote link|https://example.com/image.jpg]]
+https://example.com/user/repo/compare/88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb#hash
+com 88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb pare
+https://example.com/user/repo/commit/88fc37a3c0a4dda553bdcfc80c178a58247f42fb
+com 88fc37a3c0a4dda553bdcfc80c178a58247f42fb mit
+:+1:
+mail@domain.com
+@mention-user test
+#123
+  space  
+`
+	cases := []struct {
+		Links    markup.Links
+		IsWiki   bool
+		Expected string
+	}{
+		{ // 0
+			Links:  markup.Links{},
+			IsWiki: false,
+			Expected: `<p>space @mention-user<br/>
+/just/a/path.bin<br/>
+<a href="https://example.com/file.bin" rel="nofollow">https://example.com/file.bin</a><br/>
+<a href="/file.bin" rel="nofollow">local link</a><br/>
+<a href="https://example.com" rel="nofollow">remote link</a><br/>
+<a href="/src/file.bin" rel="nofollow">local link</a><br/>
+<a href="https://example.com" rel="nofollow">remote link</a><br/>
+<a href="/image.jpg" target="_blank" rel="nofollow noopener"><img src="/image.jpg" alt="local image"/></a><br/>
+<a href="https://example.com/image.jpg" target="_blank" rel="nofollow noopener"><img src="https://example.com/image.jpg" alt="remote image"/></a><br/>
+<a href="/image.jpg" rel="nofollow"><img src="/image.jpg" title="local image" alt="local image"/></a><br/>
+<a href="https://example.com/image.jpg" rel="nofollow"><img src="https://example.com/image.jpg" title="remote link" alt="remote link"/></a><br/>
+<a href="https://example.com/user/repo/compare/88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb#hash" rel="nofollow">https://example.com/user/repo/compare/88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb#hash</a><br/>
+com 88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb pare<br/>
+<a href="https://example.com/user/repo/commit/88fc37a3c0a4dda553bdcfc80c178a58247f42fb" rel="nofollow">https://example.com/user/repo/commit/88fc37a3c0a4dda553bdcfc80c178a58247f42fb</a><br/>
+com 88fc37a3c0a4dda553bdcfc80c178a58247f42fb mit<br/>
+<span class="emoji" aria-label="thumbs up">👍</span><br/>
+<a href="mailto:mail@domain.com" rel="nofollow">mail@domain.com</a><br/>
+@mention-user test<br/>
+#123<br/>
+space</p>
+`,
+		},
+		{ // 1
+			Links:  markup.Links{},
+			IsWiki: true,
+			Expected: `<p>space @mention-user<br/>
+/just/a/path.bin<br/>
+<a href="https://example.com/file.bin" rel="nofollow">https://example.com/file.bin</a><br/>
+<a href="/wiki/file.bin" rel="nofollow">local link</a><br/>
+<a href="https://example.com" rel="nofollow">remote link</a><br/>
+<a href="/wiki/file.bin" rel="nofollow">local link</a><br/>
+<a href="https://example.com" rel="nofollow">remote link</a><br/>
+<a href="/wiki/raw/image.jpg" target="_blank" rel="nofollow noopener"><img src="/wiki/raw/image.jpg" alt="local image"/></a><br/>
+<a href="https://example.com/image.jpg" target="_blank" rel="nofollow noopener"><img src="https://example.com/image.jpg" alt="remote image"/></a><br/>
+<a href="/wiki/raw/image.jpg" rel="nofollow"><img src="/wiki/raw/image.jpg" title="local image" alt="local image"/></a><br/>
+<a href="https://example.com/image.jpg" rel="nofollow"><img src="https://example.com/image.jpg" title="remote link" alt="remote link"/></a><br/>
+<a href="https://example.com/user/repo/compare/88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb#hash" rel="nofollow">https://example.com/user/repo/compare/88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb#hash</a><br/>
+com 88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb pare<br/>
+<a href="https://example.com/user/repo/commit/88fc37a3c0a4dda553bdcfc80c178a58247f42fb" rel="nofollow">https://example.com/user/repo/commit/88fc37a3c0a4dda553bdcfc80c178a58247f42fb</a><br/>
+com 88fc37a3c0a4dda553bdcfc80c178a58247f42fb mit<br/>
+<span class="emoji" aria-label="thumbs up">👍</span><br/>
+<a href="mailto:mail@domain.com" rel="nofollow">mail@domain.com</a><br/>
+@mention-user test<br/>
+#123<br/>
+space</p>
+`,
+		},
+		{ // 2
+			Links: markup.Links{
+				Base: "https://gitea.io/",
+			},
+			IsWiki: false,
+			Expected: `<p>space @mention-user<br/>
+/just/a/path.bin<br/>
+<a href="https://example.com/file.bin" rel="nofollow">https://example.com/file.bin</a><br/>
+<a href="https://gitea.io/file.bin" rel="nofollow">local link</a><br/>
+<a href="https://example.com" rel="nofollow">remote link</a><br/>
+<a href="https://gitea.io/src/file.bin" rel="nofollow">local link</a><br/>
+<a href="https://example.com" rel="nofollow">remote link</a><br/>
+<a href="https://gitea.io/image.jpg" target="_blank" rel="nofollow noopener"><img src="https://gitea.io/image.jpg" alt="local image"/></a><br/>
+<a href="https://example.com/image.jpg" target="_blank" rel="nofollow noopener"><img src="https://example.com/image.jpg" alt="remote image"/></a><br/>
+<a href="https://gitea.io/image.jpg" rel="nofollow"><img src="https://gitea.io/image.jpg" title="local image" alt="local image"/></a><br/>
+<a href="https://example.com/image.jpg" rel="nofollow"><img src="https://example.com/image.jpg" title="remote link" alt="remote link"/></a><br/>
+<a href="https://example.com/user/repo/compare/88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb#hash" rel="nofollow">https://example.com/user/repo/compare/88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb#hash</a><br/>
+com 88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb pare<br/>
+<a href="https://example.com/user/repo/commit/88fc37a3c0a4dda553bdcfc80c178a58247f42fb" rel="nofollow">https://example.com/user/repo/commit/88fc37a3c0a4dda553bdcfc80c178a58247f42fb</a><br/>
+com 88fc37a3c0a4dda553bdcfc80c178a58247f42fb mit<br/>
+<span class="emoji" aria-label="thumbs up">👍</span><br/>
+<a href="mailto:mail@domain.com" rel="nofollow">mail@domain.com</a><br/>
+@mention-user test<br/>
+#123<br/>
+space</p>
+`,
+		},
+		{ // 3
+			Links: markup.Links{
+				Base: "https://gitea.io/",
+			},
+			IsWiki: true,
+			Expected: `<p>space @mention-user<br/>
+/just/a/path.bin<br/>
+<a href="https://example.com/file.bin" rel="nofollow">https://example.com/file.bin</a><br/>
+<a href="https://gitea.io/wiki/file.bin" rel="nofollow">local link</a><br/>
+<a href="https://example.com" rel="nofollow">remote link</a><br/>
+<a href="https://gitea.io/wiki/file.bin" rel="nofollow">local link</a><br/>
+<a href="https://example.com" rel="nofollow">remote link</a><br/>
+<a href="https://gitea.io/wiki/raw/image.jpg" target="_blank" rel="nofollow noopener"><img src="https://gitea.io/wiki/raw/image.jpg" alt="local image"/></a><br/>
+<a href="https://example.com/image.jpg" target="_blank" rel="nofollow noopener"><img src="https://example.com/image.jpg" alt="remote image"/></a><br/>
+<a href="https://gitea.io/wiki/raw/image.jpg" rel="nofollow"><img src="https://gitea.io/wiki/raw/image.jpg" title="local image" alt="local image"/></a><br/>
+<a href="https://example.com/image.jpg" rel="nofollow"><img src="https://example.com/image.jpg" title="remote link" alt="remote link"/></a><br/>
+<a href="https://example.com/user/repo/compare/88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb#hash" rel="nofollow">https://example.com/user/repo/compare/88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb#hash</a><br/>
+com 88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb pare<br/>
+<a href="https://example.com/user/repo/commit/88fc37a3c0a4dda553bdcfc80c178a58247f42fb" rel="nofollow">https://example.com/user/repo/commit/88fc37a3c0a4dda553bdcfc80c178a58247f42fb</a><br/>
+com 88fc37a3c0a4dda553bdcfc80c178a58247f42fb mit<br/>
+<span class="emoji" aria-label="thumbs up">👍</span><br/>
+<a href="mailto:mail@domain.com" rel="nofollow">mail@domain.com</a><br/>
+@mention-user test<br/>
+#123<br/>
+space</p>
+`,
+		},
+		{ // 4
+			Links: markup.Links{
+				Base: "/relative/path",
+			},
+			IsWiki: false,
+			Expected: `<p>space @mention-user<br/>
+/just/a/path.bin<br/>
+<a href="https://example.com/file.bin" rel="nofollow">https://example.com/file.bin</a><br/>
+<a href="/relative/path/file.bin" rel="nofollow">local link</a><br/>
+<a href="https://example.com" rel="nofollow">remote link</a><br/>
+<a href="/relative/path/src/file.bin" rel="nofollow">local link</a><br/>
+<a href="https://example.com" rel="nofollow">remote link</a><br/>
+<a href="/relative/path/image.jpg" target="_blank" rel="nofollow noopener"><img src="/relative/path/image.jpg" alt="local image"/></a><br/>
+<a href="https://example.com/image.jpg" target="_blank" rel="nofollow noopener"><img src="https://example.com/image.jpg" alt="remote image"/></a><br/>
+<a href="/relative/path/image.jpg" rel="nofollow"><img src="/relative/path/image.jpg" title="local image" alt="local image"/></a><br/>
+<a href="https://example.com/image.jpg" rel="nofollow"><img src="https://example.com/image.jpg" title="remote link" alt="remote link"/></a><br/>
+<a href="https://example.com/user/repo/compare/88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb#hash" rel="nofollow">https://example.com/user/repo/compare/88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb#hash</a><br/>
+com 88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb pare<br/>
+<a href="https://example.com/user/repo/commit/88fc37a3c0a4dda553bdcfc80c178a58247f42fb" rel="nofollow">https://example.com/user/repo/commit/88fc37a3c0a4dda553bdcfc80c178a58247f42fb</a><br/>
+com 88fc37a3c0a4dda553bdcfc80c178a58247f42fb mit<br/>
+<span class="emoji" aria-label="thumbs up">👍</span><br/>
+<a href="mailto:mail@domain.com" rel="nofollow">mail@domain.com</a><br/>
+@mention-user test<br/>
+#123<br/>
+space</p>
+`,
+		},
+		{ // 5
+			Links: markup.Links{
+				Base: "/relative/path",
+			},
+			IsWiki: true,
+			Expected: `<p>space @mention-user<br/>
+/just/a/path.bin<br/>
+<a href="https://example.com/file.bin" rel="nofollow">https://example.com/file.bin</a><br/>
+<a href="/relative/path/wiki/file.bin" rel="nofollow">local link</a><br/>
+<a href="https://example.com" rel="nofollow">remote link</a><br/>
+<a href="/relative/path/wiki/file.bin" rel="nofollow">local link</a><br/>
+<a href="https://example.com" rel="nofollow">remote link</a><br/>
+<a href="/relative/path/wiki/raw/image.jpg" target="_blank" rel="nofollow noopener"><img src="/relative/path/wiki/raw/image.jpg" alt="local image"/></a><br/>
+<a href="https://example.com/image.jpg" target="_blank" rel="nofollow noopener"><img src="https://example.com/image.jpg" alt="remote image"/></a><br/>
+<a href="/relative/path/wiki/raw/image.jpg" rel="nofollow"><img src="/relative/path/wiki/raw/image.jpg" title="local image" alt="local image"/></a><br/>
+<a href="https://example.com/image.jpg" rel="nofollow"><img src="https://example.com/image.jpg" title="remote link" alt="remote link"/></a><br/>
+<a href="https://example.com/user/repo/compare/88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb#hash" rel="nofollow">https://example.com/user/repo/compare/88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb#hash</a><br/>
+com 88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb pare<br/>
+<a href="https://example.com/user/repo/commit/88fc37a3c0a4dda553bdcfc80c178a58247f42fb" rel="nofollow">https://example.com/user/repo/commit/88fc37a3c0a4dda553bdcfc80c178a58247f42fb</a><br/>
+com 88fc37a3c0a4dda553bdcfc80c178a58247f42fb mit<br/>
+<span class="emoji" aria-label="thumbs up">👍</span><br/>
+<a href="mailto:mail@domain.com" rel="nofollow">mail@domain.com</a><br/>
+@mention-user test<br/>
+#123<br/>
+space</p>
+`,
+		},
+		{ // 6
+			Links: markup.Links{
+				Base:       "/user/repo",
+				BranchPath: "branch/main",
+			},
+			IsWiki: false,
+			Expected: `<p>space @mention-user<br/>
+/just/a/path.bin<br/>
+<a href="https://example.com/file.bin" rel="nofollow">https://example.com/file.bin</a><br/>
+<a href="/user/repo/file.bin" rel="nofollow">local link</a><br/>
+<a href="https://example.com" rel="nofollow">remote link</a><br/>
+<a href="/user/repo/src/branch/main/file.bin" rel="nofollow">local link</a><br/>
+<a href="https://example.com" rel="nofollow">remote link</a><br/>
+<a href="/user/repo/media/branch/main/image.jpg" target="_blank" rel="nofollow noopener"><img src="/user/repo/media/branch/main/image.jpg" alt="local image"/></a><br/>
+<a href="https://example.com/image.jpg" target="_blank" rel="nofollow noopener"><img src="https://example.com/image.jpg" alt="remote image"/></a><br/>
+<a href="/user/repo/media/branch/main/image.jpg" rel="nofollow"><img src="/user/repo/media/branch/main/image.jpg" title="local image" alt="local image"/></a><br/>
+<a href="https://example.com/image.jpg" rel="nofollow"><img src="https://example.com/image.jpg" title="remote link" alt="remote link"/></a><br/>
+<a href="https://example.com/user/repo/compare/88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb#hash" rel="nofollow">https://example.com/user/repo/compare/88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb#hash</a><br/>
+com 88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb pare<br/>
+<a href="https://example.com/user/repo/commit/88fc37a3c0a4dda553bdcfc80c178a58247f42fb" rel="nofollow">https://example.com/user/repo/commit/88fc37a3c0a4dda553bdcfc80c178a58247f42fb</a><br/>
+com 88fc37a3c0a4dda553bdcfc80c178a58247f42fb mit<br/>
+<span class="emoji" aria-label="thumbs up">👍</span><br/>
+<a href="mailto:mail@domain.com" rel="nofollow">mail@domain.com</a><br/>
+@mention-user test<br/>
+#123<br/>
+space</p>
+`,
+		},
+		{ // 7
+			Links: markup.Links{
+				Base:       "/relative/path",
+				BranchPath: "branch/main",
+			},
+			IsWiki: true,
+			Expected: `<p>space @mention-user<br/>
+/just/a/path.bin<br/>
+<a href="https://example.com/file.bin" rel="nofollow">https://example.com/file.bin</a><br/>
+<a href="/relative/path/wiki/file.bin" rel="nofollow">local link</a><br/>
+<a href="https://example.com" rel="nofollow">remote link</a><br/>
+<a href="/relative/path/wiki/file.bin" rel="nofollow">local link</a><br/>
+<a href="https://example.com" rel="nofollow">remote link</a><br/>
+<a href="/relative/path/wiki/raw/image.jpg" target="_blank" rel="nofollow noopener"><img src="/relative/path/wiki/raw/image.jpg" alt="local image"/></a><br/>
+<a href="https://example.com/image.jpg" target="_blank" rel="nofollow noopener"><img src="https://example.com/image.jpg" alt="remote image"/></a><br/>
+<a href="/relative/path/wiki/raw/image.jpg" rel="nofollow"><img src="/relative/path/wiki/raw/image.jpg" title="local image" alt="local image"/></a><br/>
+<a href="https://example.com/image.jpg" rel="nofollow"><img src="https://example.com/image.jpg" title="remote link" alt="remote link"/></a><br/>
+<a href="https://example.com/user/repo/compare/88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb#hash" rel="nofollow">https://example.com/user/repo/compare/88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb#hash</a><br/>
+com 88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb pare<br/>
+<a href="https://example.com/user/repo/commit/88fc37a3c0a4dda553bdcfc80c178a58247f42fb" rel="nofollow">https://example.com/user/repo/commit/88fc37a3c0a4dda553bdcfc80c178a58247f42fb</a><br/>
+com 88fc37a3c0a4dda553bdcfc80c178a58247f42fb mit<br/>
+<span class="emoji" aria-label="thumbs up">👍</span><br/>
+<a href="mailto:mail@domain.com" rel="nofollow">mail@domain.com</a><br/>
+@mention-user test<br/>
+#123<br/>
+space</p>
+`,
+		},
+		{ // 8
+			Links: markup.Links{
+				Base:     "/user/repo",
+				TreePath: "sub/folder",
+			},
+			IsWiki: false,
+			Expected: `<p>space @mention-user<br/>
+/just/a/path.bin<br/>
+<a href="https://example.com/file.bin" rel="nofollow">https://example.com/file.bin</a><br/>
+<a href="/user/repo/file.bin" rel="nofollow">local link</a><br/>
+<a href="https://example.com" rel="nofollow">remote link</a><br/>
+<a href="/user/repo/src/sub/folder/file.bin" rel="nofollow">local link</a><br/>
+<a href="https://example.com" rel="nofollow">remote link</a><br/>
+<a href="/user/repo/image.jpg" target="_blank" rel="nofollow noopener"><img src="/user/repo/image.jpg" alt="local image"/></a><br/>
+<a href="https://example.com/image.jpg" target="_blank" rel="nofollow noopener"><img src="https://example.com/image.jpg" alt="remote image"/></a><br/>
+<a href="/user/repo/image.jpg" rel="nofollow"><img src="/user/repo/image.jpg" title="local image" alt="local image"/></a><br/>
+<a href="https://example.com/image.jpg" rel="nofollow"><img src="https://example.com/image.jpg" title="remote link" alt="remote link"/></a><br/>
+<a href="https://example.com/user/repo/compare/88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb#hash" rel="nofollow">https://example.com/user/repo/compare/88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb#hash</a><br/>
+com 88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb pare<br/>
+<a href="https://example.com/user/repo/commit/88fc37a3c0a4dda553bdcfc80c178a58247f42fb" rel="nofollow">https://example.com/user/repo/commit/88fc37a3c0a4dda553bdcfc80c178a58247f42fb</a><br/>
+com 88fc37a3c0a4dda553bdcfc80c178a58247f42fb mit<br/>
+<span class="emoji" aria-label="thumbs up">👍</span><br/>
+<a href="mailto:mail@domain.com" rel="nofollow">mail@domain.com</a><br/>
+@mention-user test<br/>
+#123<br/>
+space</p>
+`,
+		},
+		{ // 9
+			Links: markup.Links{
+				Base:     "/relative/path",
+				TreePath: "sub/folder",
+			},
+			IsWiki: true,
+			Expected: `<p>space @mention-user<br/>
+/just/a/path.bin<br/>
+<a href="https://example.com/file.bin" rel="nofollow">https://example.com/file.bin</a><br/>
+<a href="/relative/path/wiki/file.bin" rel="nofollow">local link</a><br/>
+<a href="https://example.com" rel="nofollow">remote link</a><br/>
+<a href="/relative/path/wiki/file.bin" rel="nofollow">local link</a><br/>
+<a href="https://example.com" rel="nofollow">remote link</a><br/>
+<a href="/relative/path/wiki/raw/image.jpg" target="_blank" rel="nofollow noopener"><img src="/relative/path/wiki/raw/image.jpg" alt="local image"/></a><br/>
+<a href="https://example.com/image.jpg" target="_blank" rel="nofollow noopener"><img src="https://example.com/image.jpg" alt="remote image"/></a><br/>
+<a href="/relative/path/wiki/raw/image.jpg" rel="nofollow"><img src="/relative/path/wiki/raw/image.jpg" title="local image" alt="local image"/></a><br/>
+<a href="https://example.com/image.jpg" rel="nofollow"><img src="https://example.com/image.jpg" title="remote link" alt="remote link"/></a><br/>
+<a href="https://example.com/user/repo/compare/88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb#hash" rel="nofollow">https://example.com/user/repo/compare/88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb#hash</a><br/>
+com 88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb pare<br/>
+<a href="https://example.com/user/repo/commit/88fc37a3c0a4dda553bdcfc80c178a58247f42fb" rel="nofollow">https://example.com/user/repo/commit/88fc37a3c0a4dda553bdcfc80c178a58247f42fb</a><br/>
+com 88fc37a3c0a4dda553bdcfc80c178a58247f42fb mit<br/>
+<span class="emoji" aria-label="thumbs up">👍</span><br/>
+<a href="mailto:mail@domain.com" rel="nofollow">mail@domain.com</a><br/>
+@mention-user test<br/>
+#123<br/>
+space</p>
+`,
+		},
+		{ // 10
+			Links: markup.Links{
+				Base:       "/user/repo",
+				BranchPath: "branch/main",
+				TreePath:   "sub/folder",
+			},
+			IsWiki: false,
+			Expected: `<p>space @mention-user<br/>
+/just/a/path.bin<br/>
+<a href="https://example.com/file.bin" rel="nofollow">https://example.com/file.bin</a><br/>
+<a href="/user/repo/file.bin" rel="nofollow">local link</a><br/>
+<a href="https://example.com" rel="nofollow">remote link</a><br/>
+<a href="/user/repo/src/branch/main/sub/folder/file.bin" rel="nofollow">local link</a><br/>
+<a href="https://example.com" rel="nofollow">remote link</a><br/>
+<a href="/user/repo/media/branch/main/sub/folder/image.jpg" target="_blank" rel="nofollow noopener"><img src="/user/repo/media/branch/main/sub/folder/image.jpg" alt="local image"/></a><br/>
+<a href="https://example.com/image.jpg" target="_blank" rel="nofollow noopener"><img src="https://example.com/image.jpg" alt="remote image"/></a><br/>
+<a href="/user/repo/media/branch/main/sub/folder/image.jpg" rel="nofollow"><img src="/user/repo/media/branch/main/sub/folder/image.jpg" title="local image" alt="local image"/></a><br/>
+<a href="https://example.com/image.jpg" rel="nofollow"><img src="https://example.com/image.jpg" title="remote link" alt="remote link"/></a><br/>
+<a href="https://example.com/user/repo/compare/88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb#hash" rel="nofollow">https://example.com/user/repo/compare/88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb#hash</a><br/>
+com 88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb pare<br/>
+<a href="https://example.com/user/repo/commit/88fc37a3c0a4dda553bdcfc80c178a58247f42fb" rel="nofollow">https://example.com/user/repo/commit/88fc37a3c0a4dda553bdcfc80c178a58247f42fb</a><br/>
+com 88fc37a3c0a4dda553bdcfc80c178a58247f42fb mit<br/>
+<span class="emoji" aria-label="thumbs up">👍</span><br/>
+<a href="mailto:mail@domain.com" rel="nofollow">mail@domain.com</a><br/>
+@mention-user test<br/>
+#123<br/>
+space</p>
+`,
+		},
+		{ // 11
+			Links: markup.Links{
+				Base:       "/relative/path",
+				BranchPath: "branch/main",
+				TreePath:   "sub/folder",
+			},
+			IsWiki: true,
+			Expected: `<p>space @mention-user<br/>
+/just/a/path.bin<br/>
+<a href="https://example.com/file.bin" rel="nofollow">https://example.com/file.bin</a><br/>
+<a href="/relative/path/wiki/file.bin" rel="nofollow">local link</a><br/>
+<a href="https://example.com" rel="nofollow">remote link</a><br/>
+<a href="/relative/path/wiki/file.bin" rel="nofollow">local link</a><br/>
+<a href="https://example.com" rel="nofollow">remote link</a><br/>
+<a href="/relative/path/wiki/raw/image.jpg" target="_blank" rel="nofollow noopener"><img src="/relative/path/wiki/raw/image.jpg" alt="local image"/></a><br/>
+<a href="https://example.com/image.jpg" target="_blank" rel="nofollow noopener"><img src="https://example.com/image.jpg" alt="remote image"/></a><br/>
+<a href="/relative/path/wiki/raw/image.jpg" rel="nofollow"><img src="/relative/path/wiki/raw/image.jpg" title="local image" alt="local image"/></a><br/>
+<a href="https://example.com/image.jpg" rel="nofollow"><img src="https://example.com/image.jpg" title="remote link" alt="remote link"/></a><br/>
+<a href="https://example.com/user/repo/compare/88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb#hash" rel="nofollow">https://example.com/user/repo/compare/88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb#hash</a><br/>
+com 88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb pare<br/>
+<a href="https://example.com/user/repo/commit/88fc37a3c0a4dda553bdcfc80c178a58247f42fb" rel="nofollow">https://example.com/user/repo/commit/88fc37a3c0a4dda553bdcfc80c178a58247f42fb</a><br/>
+com 88fc37a3c0a4dda553bdcfc80c178a58247f42fb mit<br/>
+<span class="emoji" aria-label="thumbs up">👍</span><br/>
+<a href="mailto:mail@domain.com" rel="nofollow">mail@domain.com</a><br/>
+@mention-user test<br/>
+#123<br/>
+space</p>
+`,
+		},
+	}
+
+	for i, c := range cases {
+		result, err := RenderString(&markup.RenderContext{Ctx: context.Background(), Links: c.Links, IsWiki: c.IsWiki}, input)
+		assert.NoError(t, err, "Unexpected error in testcase: %v", i)
+		assert.Equal(t, c.Expected, result, "Unexpected result in testcase %v", i)
+	}
+}