Fix Go package PURL mapping by normalizing percent-encoding in plain PURL comparison

Signed-off-by: Ajay Rajera <newajay.11r@gmail.com>

Author: Gitjay11

component_catalog/tests/test_models.py

@@ -2628,7 +2628,7 @@ def test_package_model_get_purldb_entries(self, mock_find_packages):
 
         mock_find_packages.return_value = [purldb_entry1, purldb_entry2, purldb_entry3]
         purldb_entries = package1.get_purldb_entries(user=self.user)
-        # The purldb_entry2 is excluded as the PURL differs
+        # The purldb_entry3 is excluded as its plain PURL differs (no version)
         self.assertEqual([purldb_entry1, purldb_entry2], purldb_entries)
 
     @mock.patch("dejacode_toolkit.purldb.PurlDB.find_packages")
@@ -2645,6 +2645,42 @@ def test_package_model_get_purldb_entries_plain_purls_equal(self, mock_find_pack
         purldb_entries = package1.get_purldb_entries(user=self.user)
         self.assertEqual([purldb_entry1, purldb_entry2], purldb_entries)
 
+    @mock.patch("dejacode_toolkit.purldb.PurlDB.find_packages")
+    def test_package_model_get_purldb_entries_fallback_to_purl(self, mock_find_packages):
+        """
+        Test that get_purldb_entries falls through to PURL lookup when an earlier
+        strategy (e.g. download_url) returns no results.
+
+        This covers the Go package mapping bug (issue #462): packages imported from an
+        SBOM may have an inferred download_url that PurlDB does not recognise, while
+        their PURL *is* indexed in PurlDB.  Without the fallback the PurlDB tab was
+        showing "No entries found" even though "Improve Packages from PurlDB" worked
+        (because that code path does not limit the number of requests).
+        """
+        go_purl = "pkg:golang/github.com/gin-gonic/gin@v1.9.0"
+        inferred_download_url = (
+            "https://proxy.golang.org/github.com/gin-gonic/gin/@v/v1.9.0.zip"
+        )
+        package1 = make_package(
+            self.dataspace,
+            package_url=go_purl,
+            download_url=inferred_download_url,
+        )
+        purldb_entry = {
+            "purl": go_purl,
+            "type": "golang",
+            "namespace": "github.com/gin-gonic",
+            "name": "gin",
+            "version": "v1.9.0",
+        }
+
+        # Simulate: download_url lookup fails (None), PURL lookup succeeds.
+        mock_find_packages.side_effect = [None, [purldb_entry]]
+        purldb_entries = package1.get_purldb_entries(user=self.user)
+        self.assertEqual([purldb_entry], purldb_entries)
+        # Ensure both payloads were tried (download_url first, then purl).
+        self.assertEqual(2, mock_find_packages.call_count)
+
     @mock.patch("component_catalog.models.Package.get_purldb_entries")
     def test_package_model_update_from_purldb(self, mock_get_purldb_entries):
         purldb_entry = {

component_catalog/views.py

@@ -2546,7 +2546,6 @@ def get_tab_fields(self):
 
         purldb_entries = self.object.get_purldb_entries(
             user=self.request.user,
-            max_request_call=1,
             timeout=5,
         )
         if not purldb_entries:

dje/tests/test_utils.py

@@ -531,12 +531,19 @@ def test_utils_is_purl_fragment(self):
     def test_utils_get_plain_purl(self):
         self.assertEqual("", get_plain_purl(None))
         self.assertEqual("", get_plain_purl(""))
+        # Invalid PURLs fall back to simple string split (no exception raised)
         self.assertEqual("not:a/purl", get_plain_purl("not:a/purl"))
         self.assertEqual("not:a/purl", get_plain_purl("not:a/purl"))
         self.assertEqual("pkg:npm/is-npm@1.0.0", get_plain_purl("pkg:npm/is-npm@1.0.0"))
         self.assertEqual(
             "pkg:npm/is-npm@1.0.0", get_plain_purl("pkg:npm/is-npm@1.0.0?qualifier=1#frament")
         )
+        # Percent-encoded and literal forms of the same version compare equal.
+        # "+" in a version is encoded as "%2B" by PackageURL.to_string().
+        self.assertEqual(
+            get_plain_purl("pkg:golang/github.com/foo/bar@v1.0.0%2Bincompatible"),
+            get_plain_purl("pkg:golang/github.com/foo/bar@v1.0.0+incompatible"),
+        )
 
     def test_utils_plain_purls_equal(self):
         purl1 = "pkg:npm/is-npm@1.0.0"
@@ -555,6 +562,17 @@ def test_utils_plain_purls_equal(self):
         purl2 = "pkg:npm/is-npm@2.0.0"
         self.assertFalse(plain_purls_equal(purl1, purl2))
 
+        # Go packages: percent-encoded "+" vs literal "+" in +incompatible versions
+        # must be treated as equal (issue #462).
+        purl1 = "pkg:golang/github.com/docker/docker@v19.03.15%2Bincompatible"
+        purl2 = "pkg:golang/github.com/docker/docker@v19.03.15+incompatible"
+        self.assertTrue(plain_purls_equal(purl1, purl2))
+
+        # Different versions must still be not-equal.
+        purl1 = "pkg:golang/github.com/docker/docker@v19.03.15+incompatible"
+        purl2 = "pkg:golang/github.com/docker/docker@v20.10.0+incompatible"
+        self.assertFalse(plain_purls_equal(purl1, purl2))
+
     def test_utils_localized_datetime(self):
         self.assertIsNone(localized_datetime(None))
 

dje/utils.py

@@ -663,17 +663,37 @@ def is_purl_fragment(string):
 
 
 def get_plain_purl(purl_str):
-    """Remove the qualifiers and subpath from the `purl_str```."""
+    """
+    Remove the qualifiers and subpath from the ``purl_str``.
+
+    The comparison is normalised through ``PackageURL.from_string`` so that
+    percent-encoded variants of the same PURL are treated as equal
+    (e.g. ``@v1.0.0%2Bincompatible`` and ``@v1.0.0+incompatible``).
+
+    Falls back to a simple ``split("?")`` strip when the string is not a
+    valid PURL (so callers never get an unexpected exception).
+    """
     if not purl_str:
         return ""
-    return purl_str.split("?")[0]
+    try:
+        purl = PackageURL.from_string(str(purl_str))
+        # Re-serialise without qualifiers or subpath for a canonical plain PURL.
+        return purl.to_string().split("?")[0].split("#")[0]
+    except ValueError:
+        return str(purl_str).split("?")[0]
 
 
 def plain_purls_equal(purl1, purl2):
-    """Check if two PURLs are equal, ignoring qualifiers and subpath."""
+    """Check if two PURLs are equal, ignoring qualifiers and subpath.
+
+    Percent-encoding differences (e.g. ``+`` vs ``%2B``) are normalised
+    before the comparison so semantically identical PURLs are always
+    considered equal.
+    """
     return get_plain_purl(purl1) == get_plain_purl(purl2)
 
 
+
 def remove_empty_values(input_dict):
     """
     Return a new dict not including empty value entries from `input_dict`.