fix: report the source package's version, not only its name

`get_packages` named the Debian source package and never its version, so a
consumer was handed two numbers on different axes and no way to tell.

OSV states Debian ranges in *source* versions. libldb2 is
2:2.11.0+samba4.22.11+dfsg-… while its source, samba, is 2:4.22.11+dfsg-…;
comparing the first against a samba range is meaningless, and dpkg reads
ldb's 2.11.0 as older than the 2:4.17.4+dfsg-1 that fixed CVE-2022-44640.
Reporting the source without its version is worse than reporting neither,
because it looks usable.

Measured on three live Proxmox nodes: every one of their 2 349 packages
was in that state — 802 of 802, 774 of 774, 773 of 773 — while twenty
non-Proxmox hosts had both fields. It was not a parsing bug. The
dpkg-query format string never asked for ${source:Version}, so nothing
downstream could have recovered it.

Now asked for and reported, with the same fallback napalm-linux uses:
dpkg leaves the field empty when it equals Version, and an older dpkg
leaves it empty because it does not know the field at all. Neither may
produce a package without a coordinate.

tests/test_packages.py covers all of it, including that the *query* names
the field — the assertion that would have caught this.

napalm_proxmox/system_mixin.py

@@ -245,7 +245,8 @@ class ProxmoxSystemMixin:
         # Installed packages via SSH dpkg-query
         raw = self._exec_ssh_command(
             "dpkg-query -W -f="
-            "'${Package}\\t${Version}\\t${db:Status-Status}\\t${Installed-Size}\\t${source:Package}\\n'"
+            "'${Package}\\t${Version}\\t${db:Status-Status}\\t${Installed-Size}"
+            "\\t${source:Package}\\t${source:Version}\\n'"
             " 2>/dev/null"
         )
         result: list[_JsonDict] = []
@@ -260,6 +261,19 @@ class ProxmoxSystemMixin:
             # Debian source package (differs from the binary for split packages,
             # e.g. openssh-server → openssh). Needed for accurate OSV matching.
             source_package = parts[4] if len(parts) > 4 and parts[4] else name
+            # And its version, which is a different number from this package's.
+            #
+            # OSV states Debian ranges in *source* versions, so a consumer given
+            # the source package and only the binary version compares two
+            # unrelated numbers: libldb2 is 2:2.11.0+samba4.22.11+dfsg-… while
+            # its source, samba, is 2:4.22.11+dfsg-…. Reporting the source
+            # without its version is worse than reporting neither, because it
+            # looks usable. Every package on all three Proxmox nodes was in that
+            # state — the format string never asked for the field.
+            #
+            # dpkg leaves it empty when it equals `Version`, and so does an
+            # older dpkg that does not know the field at all.
+            source_version = parts[5] if len(parts) > 5 and parts[5] else version
             if not name or status != "installed":
                 continue
             size_bytes = int(size_kb) * 1024 if size_kb.isdigit() else 0
@@ -271,6 +285,7 @@ class ProxmoxSystemMixin:
                 "size": size_bytes,
                 "source": "pve",
                 "source_package": source_package,
+                "source_version": source_version,
                 "upgrade_version": upgradable.get(name, ""),
             })
         return result

tests/test_packages.py

@@ -0,0 +1,67 @@
+"""`get_packages` and the source coordinate OSV matching needs.
+
+A Proxmox node is a Debian host, so its packages are matched against Debian
+advisories — and OSV states those ranges in *source* package versions. Reporting
+the source package without its version leaves a consumer holding two numbers on
+different axes: `libldb2` is `2:2.11.0+samba4.22.11+dfsg-…` while its source,
+samba, is `2:4.22.11+dfsg-…`, and comparing the first against a samba range is
+meaningless.
+
+Measured before this was fixed: on three Proxmox nodes, **every one** of their
+2 349 packages carried a source package and no source version — 802 of 802,
+774 of 774, 773 of 773 — while twenty non-Proxmox hosts had both. The format
+string simply never asked for the field.
+"""
+
+from __future__ import annotations
+
+import pytest
+
+# `${Package}\t${Version}\t${db:Status-Status}\t${Installed-Size}\t${source:Package}\t${source:Version}`
+DPKG = (
+    "openssh-server\t1:9.2p1-2\tinstalled\t1024\topenssh\t1:9.2p1-2\n"
+    "libldb2\t2:2.11.0+samba4.22.11+dfsg-0+deb13u1\tinstalled\t512\tsamba\t2:4.22.11+dfsg-0+deb13u1\n"
+    "curl\t7.88.1-10\tinstalled\t256\t\t\n"
+)
+
+
+@pytest.mark.parametrize("driver_with_exec", [DPKG], indirect=True)
+def test_the_source_version_is_reported(driver_with_exec):
+    """The field the whole fix is about."""
+    packages = {p["name"]: p for p in driver_with_exec.get_packages()}
+
+    assert packages["libldb2"]["source_package"] == "samba"
+    assert packages["libldb2"]["source_version"] == "2:4.22.11+dfsg-0+deb13u1"
+
+
+@pytest.mark.parametrize("driver_with_exec", [DPKG], indirect=True)
+def test_the_binary_version_is_kept_beside_it(driver_with_exec):
+    """Both are wanted: one says what is installed, the other is the axis the
+    advisory's range is stated on."""
+    libldb2 = {p["name"]: p for p in driver_with_exec.get_packages()}["libldb2"]
+
+    assert libldb2["version"] == "2:2.11.0+samba4.22.11+dfsg-0+deb13u1"
+
+
+@pytest.mark.parametrize("driver_with_exec", [DPKG], indirect=True)
+def test_an_empty_source_falls_back_to_the_package_itself(driver_with_exec):
+    """dpkg leaves both fields empty when the source is the package — and an
+    older dpkg leaves them empty because it does not know the field at all.
+    Neither may produce a package with no coordinate."""
+    curl = {p["name"]: p for p in driver_with_exec.get_packages()}["curl"]
+
+    assert curl["source_package"] == "curl"
+    assert curl["source_version"] == "7.88.1-10"
+
+
+def test_the_query_asks_for_the_field():
+    """The defect was in the format string, not in the parsing: the driver
+    reported a source package it had asked for and a source version it had
+    not, so no amount of parsing could have produced one."""
+    import inspect
+
+    from napalm_proxmox import system_mixin
+
+    source = inspect.getsource(system_mixin.ProxmoxSystemMixin.get_packages)
+
+    assert "source:Version" in source