From aa714191b20e5fecc7752d5402aef7d0adb35f7e Mon Sep 17 00:00:00 2001
From: Charlie Marsh <charlie.r.marsh@gmail.com>
Date: Sat, 4 Apr 2026 22:17:02 -0400
Subject: [PATCH] Sort by comparator to break specifier ties

---
 crates/uv-pep440/src/version_specifier.rs | 18 +++++-
 crates/uv/tests/it/sync.rs                | 73 +++++++++++++++++++++++
 2 files changed, 90 insertions(+), 1 deletion(-)

diff --git a/crates/uv-pep440/src/version_specifier.rs b/crates/uv-pep440/src/version_specifier.rs
index 17928b881218c..c86e8004c12d1 100644
--- a/crates/uv-pep440/src/version_specifier.rs
+++ b/crates/uv-pep440/src/version_specifier.rs
@@ -67,7 +67,14 @@ impl VersionSpecifiers {
     fn from_unsorted(mut specifiers: Vec<VersionSpecifier>) -> Self {
         // TODO(konsti): This seems better than sorting on insert and not getting the size hint,
         // but i haven't measured it.
-        specifiers.sort_by(|a, b| a.version().cmp(b.version()));
+        //
+        // Tie-break on the operator so semantically equivalent same-version intervals such as
+        // `>=1.4.4,<=1.4.4` and `<=1.4.4,>=1.4.4` normalize to the same representation.
+        specifiers.sort_by(|a, b| {
+            a.version()
+                .cmp(b.version())
+                .then_with(|| a.operator().cmp(b.operator()))
+        });
         Self(specifiers.into_boxed_slice())
     }
 
@@ -1951,6 +1958,15 @@ mod tests {
         );
     }
 
+    #[test]
+    fn test_version_specifiers_singular_interval() {
+        let lower_then_upper = VersionSpecifiers::from_str(">=1.4.4, <=1.4.4").unwrap();
+        let upper_then_lower = VersionSpecifiers::from_str("<=1.4.4, >=1.4.4").unwrap();
+
+        assert_eq!(lower_then_upper, upper_then_lower);
+        assert_eq!(lower_then_upper.to_string(), "<=1.4.4, >=1.4.4");
+    }
+
     /// These occur in the simple api, e.g.
     /// <https://pypi.org/simple/geopandas/?format=application/vnd.pypi.simple.v1+json>
     #[test]
diff --git a/crates/uv/tests/it/sync.rs b/crates/uv/tests/it/sync.rs
index 61a7e6d13a225..ab37a54afbc08 100644
--- a/crates/uv/tests/it/sync.rs
+++ b/crates/uv/tests/it/sync.rs
@@ -5405,6 +5405,79 @@ fn read_metadata_statically_over_the_cache() -> Result<()> {
     Ok(())
 }
 
+/// Accept equivalent singular version intervals in static `requires-dist` metadata.
+///
+/// See: <https://github.com/astral-sh/uv/issues/17639>
+#[test]
+fn no_install_project_singular_interval_requires_dist() -> Result<()> {
+    let context = uv_test::test_context!("3.12");
+
+    let pyproject_toml = context.temp_dir.child("pyproject.toml");
+    pyproject_toml.write_str(
+        r#"
+        [project]
+        name = "project"
+        requires-python = ">=3.12"
+        dynamic = ["version"]
+        dependencies = ["iniconfig>=2.0.0,<=2.0.0"]
+
+        [build-system]
+        requires = ["hatchling"]
+        build-backend = "hatchling.build"
+
+        [tool.uv]
+        cache-keys = [{ file = "pyproject.toml" }, { file = "src/__about__.py" }]
+
+        [tool.hatch.version]
+        path = "src/__about__.py"
+        scheme = "standard"
+        "#,
+    )?;
+    context
+        .temp_dir
+        .child("src")
+        .child("__about__.py")
+        .write_str("__version__ = '0.1.0'")?;
+    context
+        .temp_dir
+        .child("src")
+        .child("project")
+        .child("__init__.py")
+        .touch()?;
+
+    context.lock().assert().success();
+
+    let lock_path = context.temp_dir.join("uv.lock");
+    let lock = fs_err::read_to_string(&lock_path)?;
+    let lock = lock.replacen(
+        r#"requires-dist = [{ name = "iniconfig", specifier = ">=2.0.0,<=2.0.0" }]"#,
+        r#"requires-dist = [{ name = "iniconfig", specifier = "<=2.0.0,>=2.0.0" }]"#,
+        1,
+    );
+    assert!(
+        lock.contains(r#"requires-dist = [{ name = "iniconfig", specifier = "<=2.0.0,>=2.0.0" }]"#),
+        "expected to rewrite the dynamic package metadata in `uv.lock`"
+    );
+    fs_err::write(&lock_path, lock)?;
+
+    fs_err::remove_dir_all(&context.cache_dir)?;
+    fs_err::remove_file(context.temp_dir.join("src").join("__about__.py"))?;
+
+    uv_snapshot!(context.filters(), context.sync().arg("--locked").arg("--no-install-project"), @"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    Resolved 2 packages in [TIME]
+    Prepared 1 package in [TIME]
+    Installed 1 package in [TIME]
+     + iniconfig==2.0.0
+    ");
+
+    Ok(())
+}
+
 /// Avoid syncing the project package when `--no-install-project` is provided.
 #[test]
 fn no_install_project() -> Result<()> {