TST: exercise transitive RPATH lookup with a shared library chain

tests/packages/sharedlib-chain/chainhead/__init__.py

@@ -0,0 +1,3 @@
+# SPDX-FileCopyrightText: 2026 The meson-python developers
+#
+# SPDX-License-Identifier: MIT

tests/packages/sharedlib-chain/chainhead/leaf/leaf.c

@@ -0,0 +1,7 @@
+// SPDX-FileCopyrightText: 2026 The meson-python developers
+//
+// SPDX-License-Identifier: MIT
+
+int leaf(void) {
+    return 7;
+}

tests/packages/sharedlib-chain/chainhead/leaf/meson.build

@@ -0,0 +1,9 @@
+# SPDX-FileCopyrightText: 2026 The meson-python developers
+#
+# SPDX-License-Identifier: MIT
+
+leaf = shared_library(
+    'leaf', 'leaf.c',
+    install: true,
+    install_dir: py.get_install_dir() / 'chainhead/lib',
+)

tests/packages/sharedlib-chain/chainhead/meson.build

@@ -0,0 +1,16 @@
+# SPDX-FileCopyrightText: 2026 The meson-python developers
+#
+# SPDX-License-Identifier: MIT
+
+subdir('leaf')
+subdir('middle')
+
+py.install_sources('__init__.py', subdir: 'chainhead')
+
+py.extension_module(
+    'chain', 'module.c',
+    link_with: middle,
+    install: true,
+    subdir: 'chainhead',
+    install_rpath: '$ORIGIN/lib',
+)

tests/packages/sharedlib-chain/chainhead/middle/meson.build

@@ -0,0 +1,10 @@
+# SPDX-FileCopyrightText: 2026 The meson-python developers
+#
+# SPDX-License-Identifier: MIT
+
+middle = shared_library(
+    'middle', 'middle.c',
+    link_with: leaf,
+    install: true,
+    install_dir: py.get_install_dir() / 'chainhead/lib',
+)

tests/packages/sharedlib-chain/chainhead/middle/middle.c

@@ -0,0 +1,9 @@
+// SPDX-FileCopyrightText: 2026 The meson-python developers
+//
+// SPDX-License-Identifier: MIT
+
+extern int leaf(void);
+
+int middle(void) {
+    return leaf() + 1;
+}

tests/packages/sharedlib-chain/chainhead/module.c

@@ -0,0 +1,24 @@
+// SPDX-FileCopyrightText: 2026 The meson-python developers
+//
+// SPDX-License-Identifier: MIT
+
+#include <Python.h>
+
+extern int middle(void);
+
+static PyObject *value(PyObject *self, PyObject *args) {
+    return PyLong_FromLong(middle());
+}
+
+static PyMethodDef methods[] = {
+    {"value", value, METH_NOARGS, NULL},
+    {NULL, NULL, 0, NULL},
+};
+
+static struct PyModuleDef module = {
+    PyModuleDef_HEAD_INIT, "chain", NULL, -1, methods,
+};
+
+PyMODINIT_FUNC PyInit_chain(void) {
+    return PyModule_Create(&module);
+}

tests/packages/sharedlib-chain/meson.build

@@ -0,0 +1,14 @@
+# SPDX-FileCopyrightText: 2026 The meson-python developers
+#
+# SPDX-License-Identifier: MIT
+
+project('sharedlib-chain', 'c', version: '1.0.0')
+
+py = import('python').find_installation(pure: false)
+
+# Request RPATH rather than RUNPATH when supported by the linker.
+if meson.get_compiler('c').has_link_argument('-Wl,--disable-new-dtags')
+    add_project_link_arguments('-Wl,--disable-new-dtags', language: 'c')
+endif
+
+subdir('chainhead')

tests/packages/sharedlib-chain/pyproject.toml

@@ -0,0 +1,7 @@
+# SPDX-FileCopyrightText: 2026 The meson-python developers
+#
+# SPDX-License-Identifier: MIT
+
+[build-system]
+build-backend = 'mesonpy'
+requires = ['meson-python']

tests/test_wheel.py

@@ -309,6 +309,23 @@ def test_rpath_install_precedence(venv, wheel_same_name_sharedlibs, tmp_path):
     assert int(output) == 42
 
 
+@pytest.mark.skipif(MESON_VERSION < (1, 6, 0), reason='meson too old')
+@pytest.mark.skipif(sys.platform in {'win32', 'cygwin'}, reason='requires RPATH support')
+@pytest.mark.filterwarnings('ignore:translated "install_rpath" argument for ')
+def test_rpath_transitive_lookup(venv, wheel_sharedlib_chain, tmp_path):
+    artifact = wheel.wheelfile.WheelFile(wheel_sharedlib_chain)
+    artifact.extractall(tmp_path)
+
+    origin = '@loader_path' if sys.platform == 'darwin' else '$ORIGIN'
+    rpath = mesonpy._rpath.get_rpath(tmp_path / 'chainhead' / f'chain{EXT_SUFFIX}')
+    assert f'{origin}/lib' in rpath
+
+    venv.pip('install', wheel_sharedlib_chain)
+    # RUNPATH cannot supply the extension's search path to its indirect dependency on glibc.
+    output = venv.python('-c', 'from chainhead import chain; print(chain.value())')
+    assert int(output) == 8
+
+
 @pytest.mark.skipif(sys.platform in {'win32', 'cygwin'}, reason='requires executable bit support')
 def test_executable_bit(wheel_executable_bit):
     artifact = wheel.wheelfile.WheelFile(wheel_executable_bit)