tpl/tplimpl: Resolve render hook destinations with leading ./

Closes #12514

tpl/tplimpl/render_hook_integration_test.go

@@ -51,7 +51,8 @@ title: s1/p1
 title: s1/p2
 ---
 [500](a.txt) // global resource
-[600](b.txt) // page resource
+[510](b.txt) // page resource
+[520](./b.txt) // page resource
 -- content/s1/p2/b.txt --
 irrelevant
 -- content/s1/p3.md --
@@ -125,12 +126,14 @@ title: s1/p3
 
 	b.AssertFileContent("public/s1/p2/index.html",
 		`<a href="/a.txt">500</a>`,
-		`<a href="/s1/p2/b.txt">600</a>`,
+		`<a href="/s1/p2/b.txt">510</a>`,
+		`<a href="/s1/p2/b.txt">520</a>`,
 	)
 }
 
 // Issue 12203
 // Issue 12468
+// Issue 12514
 func TestEmbeddedImageRenderHook(t *testing.T) {
 	t.Parallel()
 
@@ -145,7 +148,9 @@ block = false
 [markup.goldmark.renderHooks.image]
 enableDefault = true
 -- content/p1/index.md --
-![alt](pixel.png?a=b&c=d#fragment)
+![alt1](./pixel.png)
+
+![alt2](pixel.png?a=b&c=d#fragment)
 {.foo #bar}
 -- content/p1/pixel.png --
 iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mNkYPhfDwAChwGA60e6kgAAAABJRU5ErkJggg==
@@ -154,10 +159,16 @@ iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mNkYPhfDwAChwGA60e6kgAA
 `
 
 	b := hugolib.Test(t, files)
-	b.AssertFileContent("public/p1/index.html", `<img alt="alt" src="/dir/p1/pixel.png?a=b&c=d#fragment">`)
+	b.AssertFileContent("public/p1/index.html",
+		`<img alt="alt1" src="/dir/p1/pixel.png">`,
+		`<img alt="alt2" src="/dir/p1/pixel.png?a=b&c=d#fragment">`,
+	)
 
 	files = strings.Replace(files, "block = false", "block = true", -1)
 
 	b = hugolib.Test(t, files)
-	b.AssertFileContent("public/p1/index.html", `<img alt="alt" class="foo" id="bar" src="/dir/p1/pixel.png?a=b&c=d#fragment">`)
+	b.AssertFileContent("public/p1/index.html",
+		`<img alt="alt1" src="/dir/p1/pixel.png">`,
+		`<img alt="alt2" class="foo" id="bar" src="/dir/p1/pixel.png?a=b&c=d#fragment">`,
+	)
 }