Fixes a bug related to legacy gems.

fixes: #209

CHANGES/209.bugfix

@@ -0,0 +1 @@
+Fixed a bug where legacy gems would cause an exception in pulpcore-content.

pulp_gem/specs.py

@@ -1,4 +1,5 @@
 from collections import namedtuple
+from logging import getLogger
 
 import aiofiles
 import datetime
@@ -14,6 +15,8 @@
 import rubymarshal.reader
 
 
+log = getLogger(__name__)
+
 NAME_REGEX = re.compile(r"[\w\.-]+")
 VERSION_REGEX = re.compile(r"\d+(?:\.\d+)*")
 PRERELEASE_VERSION_REGEX = NAME_REGEX
@@ -274,6 +277,41 @@ def yaml_constructor(cls, loader, node):
         result.attributes = {f"@{key}": value for key, value in values.items()}
         result.attributes["@type"] = rubymarshal.classes.Symbol(result.attributes["@type"][1:])
 
+    @property
+    def requirement(self):
+        # From:
+        # File lib/rubygems/dependency.rb, line 116
+
+        # @version_requirements and @version_requirement are legacy ivar
+        # names, and supported here because older gems need to keep
+        # working and Dependency doesn't implement marshal_dump and
+        # marshal_load. In a happier world, this would be an
+        # attr_accessor. The horrifying instance_variable_get you see
+        # below is also the legacy of some old restructurings.
+        #
+        # Note also that because of backwards compatibility (loading new
+        # gems in an old RubyGems installation), we can't add explicit
+        # marshaling to this class until we want to make a big
+        # break. Maybe 2.0.
+        #
+        # Children, define explicit marshal and unmarshal behavior for
+        # public classes. Marshal formats are part of your public API.
+
+        if result := self.attributes.get("@requirement"):
+            return result
+        if version_requirement := self.attributes.pop("@version_requirement", None):
+            log.warn(
+                "You are attempting to process a really old gem. "
+                "If this codepath fails, please report an issue with this gem "
+                "so we actually have something to experiment on."
+            )
+            version = GemVersion()
+            version.marshal_load([version_requirement.attributes["@version"]])
+            requirement = GemRequirement()
+            requirement._private_data[0] = [[">=", version]]
+            self.attributes["@version_requirements"] = requirement
+        return self.attributes.get("@version_requirements")
+
 
 class RubyTime(rubymarshal.classes.UserDef):
     ruby_class_name = "Time"
@@ -352,7 +390,7 @@ def analyse_gem(file_obj):
             gem_info[key] = requirement.to_s()
     if (dependencies := data._private_data.get("dependencies")) is not None:
         gem_info["dependencies"] = {
-            dep.attributes["@name"]: dep.attributes["@requirement"].to_s() for dep in dependencies
+            dep.attributes["@name"]: dep.requirement.to_s() for dep in dependencies
         }
     zdata = zlib.compress(rubymarshal.writer.writes(data))
     return gem_info, zdata

pulp_gem/tests/functional/api/test_pull_through.py

@@ -60,18 +60,22 @@ def test_pull_through_install(
     remote2 = gem_remote_factory()
     distribution2 = gem_distribution_factory(remote=remote2.pulp_href)
 
-    for dis, gem in ((distribution, "a"), (distribution2, "beryl")):
-        cmd = ["gem", "i", "--remote", "--clear-sources", "-s", dis.base_url, gem, "-v", "0.1.0"]
+    for dis, gem, version in (
+        (distribution, "a", "0.1.0"),
+        (distribution2, "beryl", "0.1.0"),
+        (distribution, "ruby-hmac", "0.4.0"),
+    ):
+        cmd = ["gem", "i", "--remote", "--clear-sources", "-s", dis.base_url, gem, "-v", version]
 
         out = subprocess.run(cmd, stdout=subprocess.PIPE)
-        assert f"Successfully installed {gem}-0.1.0" in out.stdout.decode("utf-8")
+        assert f"Successfully installed {gem}-{version}" in out.stdout.decode("utf-8")
 
-        r = gem_content_api_client.list(name=gem, version="0.1.0")
+        r = gem_content_api_client.list(name=gem, version=version)
         assert r.count == 1
         assert r.results[0].name == gem
-        assert r.results[0].version == "0.1.0"
+        assert r.results[0].version == version
 
-        subprocess.run(("gem", "uninstall", gem, "-v", "0.1.0"))
+        subprocess.run(("gem", "uninstall", gem, "-v", version))
 
     content_after = gem_content_api_client.list().count
-    assert content_before + 2 == content_after
+    assert content_before + 3 == content_after