From 7e6aa80c6a8c553ba76824da612d409b4b5dab14 Mon Sep 17 00:00:00 2001
From: bensynapse <118375461+bensynapse@users.noreply.github.com>
Date: Sat, 10 Oct 2026 10:15:42 +0300
Subject: [PATCH] Preserve numeric zero in named URI parameters

Numeric zero was treated as an empty value in query and semicolon
expansions. Keep its quoted text so offset=0 stays in the expanded URI.
---
 tests/test_uritemplate.py | 28 ++++++++++++++++++++++++++++
 uritemplate/variable.py   | 11 +++++------
 2 files changed, 33 insertions(+), 6 deletions(-)

diff --git a/tests/test_uritemplate.py b/tests/test_uritemplate.py
index dfe19f5..e796582 100644
--- a/tests/test_uritemplate.py
+++ b/tests/test_uritemplate.py
@@ -664,6 +664,34 @@ def test_expand(self) -> None:
         self.assertEqual(expand("{/zero}", self.context), "/0")
         self.assertEqual(expand("{/zero,a_float}", self.context), "/0/3.1415")
 
+    def test_zero_parameter_expansions(self) -> None:
+        cases: t.List[t.Tuple[variable.ScalarVariableValue, str]] = [
+            (0, "0"),
+            (0.0, "0.0"),
+            (-0.0, "-0.0"),
+            (0j, "0j"),
+        ]
+        for value, expected in cases:
+            for operator in ("?", "&", ";"):
+                for modifier in ("", "*"):
+                    template = f"{{{operator}zero{modifier}}}"
+                    with self.subTest(template=template, value=value):
+                        self.assertEqual(
+                            expand(template, {"zero": value}),
+                            f"{operator}zero={expected}",
+                        )
+
+    def test_empty_parameter_expansions(self) -> None:
+        for operator, expected in (
+            ("?", "?zero="),
+            ("&", "&zero="),
+            (";", ";zero"),
+        ):
+            template = f"{{{operator}zero}}"
+            with self.subTest(template=template):
+                self.assertEqual(expand(template, {"zero": ""}), expected)
+                self.assertEqual(expand(template, {"zero": None}), "")
+
 
 if __name__ == "__main__":
     unittest.main()
diff --git a/uritemplate/variable.py b/uritemplate/variable.py
index 1f7993c..f0d6ddb 100644
--- a/uritemplate/variable.py
+++ b/uritemplate/variable.py
@@ -310,11 +310,9 @@ def _query_expansion(
                 )
                 return f"{name}={value}"
 
-        if value:
-            value = t.cast(t.Text, value)
-            value = value[:prefix] if prefix else value
-            return f"{name}={_quote(value)}"
-        return name + "="
+        value = t.cast(t.Text, value)
+        value = value[:prefix] if prefix else value
+        return f"{name}={_quote(value)}"
 
     def _label_path_expansion(
         self,
@@ -415,8 +413,9 @@ def _semi_path_expansion(
 
         value = t.cast(t.Text, value)
         value = value[:prefix] if prefix else value
+        value = self.operator.quote(value)
         if value:
-            return f"{name}={self.operator.quote(value)}"
+            return f"{name}={value}"
 
         return name