From 71c1779c0740d2a9ac916ee33f261e7dea4b76fb Mon Sep 17 00:00:00 2001
From: Alessio Bogon <778703+youtux@users.noreply.github.com>
Date: Sun, 9 Jun 2024 09:15:08 +0200
Subject: [PATCH 1/3] Add (failing) test for trailing slash when joining with
 ""

---
 tests/test_url.py | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/tests/test_url.py b/tests/test_url.py
index 725e9465b..c71f50c6a 100644
--- a/tests/test_url.py
+++ b/tests/test_url.py
@@ -806,6 +806,15 @@ def test_div_with_dots():
             id="cleanup-query-and-fragment",
         ),
         pytest.param("", ("path/",), "http://example.com/path/", id="trailing-slash"),
+        pytest.param(
+            "",
+            (
+                "path",
+                "",
+            ),
+            "http://example.com/path/",
+            id="trailing-slash-empty-string",
+        ),
         pytest.param(
             "", ("path/", "to/"), "http://example.com/path/to/", id="duplicate-slash"
         ),

From 73e658aa4721300b049048dadc6cb32942ff5ecc Mon Sep 17 00:00:00 2001
From: Alessio Bogon <778703+youtux@users.noreply.github.com>
Date: Sun, 9 Jun 2024 09:29:13 +0200
Subject: [PATCH 2/3] Add back trailing slash when joining with ""

---
 yarl/_url.py | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/yarl/_url.py b/yarl/_url.py
index 9cca27ef8..f7ee3bf1a 100644
--- a/yarl/_url.py
+++ b/yarl/_url.py
@@ -718,9 +718,7 @@ def _make_child(self, segments, encoded=False):
         # keep the trailing slash if the last segment ends with /
         parsed = [""] if segments and segments[-1][-1:] == "/" else []
         for seg in reversed(segments):
-            if not seg:
-                continue
-            if seg[0] == "/":
+            if seg and seg[0] == "/":
                 raise ValueError(
                     f"Appending path {seg!r} starting from slash is forbidden"
                 )

From b553c6fbbc3933a13f891b19d10b17bad3e958b0 Mon Sep 17 00:00:00 2001
From: Alessio Bogon <778703+youtux@users.noreply.github.com>
Date: Sun, 9 Jun 2024 09:31:38 +0200
Subject: [PATCH 3/3] Add another test for path joining to ""

---
 tests/test_url.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/tests/test_url.py b/tests/test_url.py
index c71f50c6a..d6c88d44b 100644
--- a/tests/test_url.py
+++ b/tests/test_url.py
@@ -799,6 +799,9 @@ def test_div_with_dots():
         pytest.param(
             "/path/", ("to",), "http://example.com/path/to", id="path-with-slash"
         ),
+        pytest.param(
+            "/path", ("",), "http://example.com/path/", id="path-add-trailing-slash"
+        ),
         pytest.param(
             "/path?a=1#frag",
             ("to",),