Add real RPM fixtures and rewrite RPM-reading tests to use them

Replace the heavily-patched MockRPMHeader approach in test_rpm_reading.py
and test_rpm_checking.py with actual RPM files built from minimal spec files.

The mock approach was fragile in two ways that the reviewer flagged:
- test_skip_source_rpm only passed because the mock hardcoded arch='src',
  but real SRPMs have arch='noarch' — the test was not testing real behaviour.
- Every test carried 18 patch() calls that coupled tests to implementation
  details (which constants the code reads, whether it uses bytes or str, etc.).

New layout:

  tests/fixtures/rpms/
    specs/          - five spec files, one per test scenario
    rebuild.sh      - regenerate RPMs from specs (requires rpmbuild)
    *.noarch.rpm    - six pre-built binary RPMs
    *.src.rpm       - one pre-built source RPM

Packages (all noarch, no dist tag for cross-Fedora stability):

  revdeptest-foo        1.0   simple package, no epoch
  revdeptest-bar        1.0   different SRPM (for mixed-SRPM error test)
  revdeptest-bundled    1.0   has bundled(libfoo) and bundled(libbar) provides
  revdeptest-multi      1.0   main package with a subpackage (same SRPM)
  revdeptest-multi-sub  1.0   subpackage of revdeptest-multi
  revdeptest-epoch      9.1.0 Epoch: 1 package

test_rpm_reading.py now imports nothing from unittest.mock and carries no
rpm-module patches. It passes real paths to read_rpm_provides() and asserts
on the real header values returned by the rpm library.

test_rpm_checking.py keeps MockBase/MockPackage for the DNF layer (which has
its own test coverage) but passes real RPM files into check_rpm_files().

Remove *.spec from .gitignore (added for PyInstaller; not relevant here and
was hiding the new spec files from git).

Co-Authored-By: Claude Sonnet 4.6 (1M context) <noreply@anthropic.com>

Author: frenzymadness

.gitignore

@@ -29,7 +29,6 @@ MANIFEST
 
 # PyInstaller
 *.manifest
-*.spec
 
 # Installer logs
 pip-log.txt

tests/fixtures/rpms/rebuild.sh

@@ -0,0 +1,34 @@
+#!/usr/bin/env bash
+# Rebuild all test RPM fixtures from the spec files in specs/.
+# Run this script when you add a new spec or need to regenerate existing RPMs.
+#
+# Requirements: rpmbuild
+
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+BUILD=$(mktemp -d)
+trap 'rm -rf "$BUILD"' EXIT
+
+build_binary() {
+    rpmbuild --define "_topdir $BUILD" --define "dist %{nil}" --nodeps -bb "$1" 2>&1
+}
+
+build_source() {
+    rpmbuild --define "_topdir $BUILD" --define "dist %{nil}" --nodeps -bs "$1" 2>&1
+}
+
+for spec in "$SCRIPT_DIR"/specs/*.spec; do
+    echo "Building binary: $spec"
+    build_binary "$spec"
+done
+
+echo "Building source RPM: revdeptest-foo.spec"
+build_source "$SCRIPT_DIR/specs/revdeptest-foo.spec"
+
+cp "$BUILD"/RPMS/noarch/*.rpm "$SCRIPT_DIR"/
+cp "$BUILD"/SRPMS/*.rpm       "$SCRIPT_DIR"/
+
+echo ""
+echo "Built RPMs:"
+ls -lh "$SCRIPT_DIR"/*.rpm

tests/fixtures/rpms/revdeptest-bar-1.0-1.noarch.rpm

@@ -0,0 +1,18 @@
+Name:           revdeptest-bar
+Version:        1.0
+Release:        1
+Summary:        Test package (second SRPM) for fedora-revdep-check tests
+License:        CC0-1.0
+BuildArch:      noarch
+
+Provides:       python3dist(revdeptest-bar) = 1.0
+
+%description
+Minimal test package from a different SRPM for fedora-revdep-check unit tests.
+
+%install
+mkdir -p %{buildroot}
+
+%files
+
+%changelog