diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index b5bfa058..b9317954 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -58,6 +58,7 @@ metadata_v0:
     - ../tests/dump_internal_metadata_format.py
     - sed -i
           -e "/buildozer/d"
+          -e '/^comments\W /d'
           -e 's,maven\(\W\) false,maven\1 null,'
           metadata/dump_*/*.yaml
     - diff -uw metadata/dump_*
@@ -487,7 +488,7 @@ servergitmirrors:
     - diff repo/index-v1.jar index-v1.jar
 
 Build documentation:
-  image: debian:bullseye-backports
+  image: debian:bookworm
   <<: *apt-template
   script:
     - apt-get install make python3-sphinx python3-numpydoc python3-pydata-sphinx-theme pydocstyle fdroidserver
diff --git a/.yamllint b/.yamllint
index 6105b5d4..067a389e 100644
--- a/.yamllint
+++ b/.yamllint
@@ -2,4 +2,6 @@
 
 extends: default
 rules:
+  document-start: disable
   line-length: disable
+  truthy: disable
diff --git a/examples/Vagrantfile.yaml b/examples/Vagrantfile.yaml
index 6bf9c5ca..276f0179 100644
--- a/examples/Vagrantfile.yaml
+++ b/examples/Vagrantfile.yaml
@@ -1,3 +1,4 @@
+---
 
 # You may want to alter these before running ./makebuildserver
 
diff --git a/fdroidserver/import_subcommand.py b/fdroidserver/import_subcommand.py
index b8fb7093..03c36539 100644
--- a/fdroidserver/import_subcommand.py
+++ b/fdroidserver/import_subcommand.py
@@ -323,7 +323,7 @@ def main():
     if git_modules.exists():
         build.submodules = True
 
-    metadata.post_metadata_parse(app)
+    metadata.post_parse_yaml_metadata(app)
 
     app['Builds'].append(build)
 
diff --git a/fdroidserver/index.py b/fdroidserver/index.py
index cde814ed..d93ec586 100644
--- a/fdroidserver/index.py
+++ b/fdroidserver/index.py
@@ -878,7 +878,7 @@ def make_v1(apps, packages, repodir, repodict, requestsdict, fdroid_signing_key_
         for k, v in sorted(appdict.items()):
             if not v:
                 continue
-            if k in ('Builds', 'comments', 'metadatapath',
+            if k in ('Builds', 'metadatapath',
                      'ArchivePolicy', 'AutoName', 'AutoUpdateMode', 'MaintainerNotes',
                      'Provides', 'Repo', 'RepoType', 'RequiresRoot',
                      'UpdateCheckData', 'UpdateCheckIgnore', 'UpdateCheckMode',
diff --git a/fdroidserver/metadata.py b/fdroidserver/metadata.py
index b16f34af..15008e95 100644
--- a/fdroidserver/metadata.py
+++ b/fdroidserver/metadata.py
@@ -159,7 +159,6 @@ class App(dict):
         self.id = None
         self.metadatapath = None
         self.Builds = []
-        self.comments = {}
         self.added = None
         self.lastUpdated = None
 
@@ -607,91 +606,53 @@ def read_metadata(appids={}, sort_by_time=False):
     return apps
 
 
-def sorted_builds(builds):
-    return sorted(builds, key=lambda build: build.versionCode)
-
-
-def post_metadata_parse(app):
-    for k, v in app.items():
-        if fieldtype(k) == TYPE_LIST:
-            if isinstance(v, str):
-                app[k] = [v, ]
-            elif v:
-                app[k] = [str(i) for i in v]
-        elif fieldtype(k) == TYPE_INT:
-            if v:
-                app[k] = int(v)
-        elif fieldtype(k) == TYPE_STRING:
-            if v:
-                app[k] = str(v)
-        else:
-            if type(v) in (float, int):
-                app[k] = str(v)
-
-    builds = []
-    if 'Builds' in app:
-        for build in app.get('Builds', []):
-            if not isinstance(build, Build):
-                build = Build(build)
-            for k, v in build.items():
-                if not (v is None):
-                    if flagtype(k) == TYPE_LIST:
-                        if isinstance(v, str):
-                            build[k] = [v]
-                    elif flagtype(k) is TYPE_INT:
-                        build[k] = v
-                    elif flagtype(k) is TYPE_STRING:
-                        build[k] = str(v)
-            builds.append(build)
-
-    app['Builds'] = sorted_builds(builds)
-
-
-# Parse metadata for a single application.
-#
-#  'metadatapath' - the file path to read. The "Application ID" aka
-#               "Package Name" for the application comes from this
-#               filename. Pass None to get a blank entry.
-#
-# Returns a dictionary containing all the details of the application. There are
-# two major kinds of information in the dictionary. Keys beginning with capital
-# letters correspond directory to identically named keys in the metadata file.
-# Keys beginning with lower case letters are generated in one way or another,
-# and are not found verbatim in the metadata.
-#
-# Known keys not originating from the metadata are:
-#
-#  'comments'         - a list of comments from the metadata file. Each is
-#                       a list of the form [field, comment] where field is
-#                       the name of the field it preceded in the metadata
-#                       file. Where field is None, the comment goes at the
-#                       end of the file. Alternatively, 'build:version' is
-#                       for a comment before a particular build version.
-#  'descriptionlines' - original lines of description as formatted in the
-#                       metadata file.
-#
-
-
 def parse_metadata(metadatapath):
     """Parse metadata file, also checking the source repo for .fdroid.yml.
 
+    This function finds the relevant files, gets them parsed, converts
+    dicts into App and Build instances, and combines the results into
+    a single App instance.
+
     If this is a metadata file from fdroiddata, it will first load the
     source repo type and URL from fdroiddata, then read .fdroid.yml if
     it exists, then include the rest of the metadata as specified in
     fdroiddata, so that fdroiddata has precedence over the metadata in
     the source code.
 
+    .fdroid.yml is embedded in the app's source repo, so it is
+    "user-generated".  That means that it can have weird things in it
+    that need to be removed so they don't break the overall process,
+    e.g. if the upstream developer includes some broken field, it can
+    be overridden in the metadata file.
+
+    Parameters
+    ----------
+    metadatapath
+      The file path to read. The "Application ID" aka "Package Name"
+      for the application comes from this filename.
+
+    Raises
+    ------
+    FDroidException when there are syntax errors.
+
+    Returns
+    -------
+    Returns a dictionary containing all the details of the
+    application. There are two major kinds of information in the
+    dictionary. Keys beginning with capital letters correspond
+    directory to identically named keys in the metadata file.  Keys
+    beginning with lower case letters are generated in one way or
+    another, and are not found verbatim in the metadata.
+
     """
     metadatapath = Path(metadatapath)
     app = App()
     app.metadatapath = metadatapath.as_posix()
-    name = metadatapath.stem
-    if name != '.fdroid':
-        app.id = name
-
+    if metadatapath.stem != '.fdroid':
+        app.id = metadatapath.stem
     if metadatapath.suffix == '.yml':
         with metadatapath.open('r', encoding='utf-8') as mf:
-            parse_yaml_metadata(mf, app)
+            app.update(parse_yaml_metadata(mf))
     else:
         _warn_or_exception(_('Unknown metadata format: {path} (use: *.yml)')
                            .format(path=metadatapath))
@@ -712,8 +673,13 @@ def parse_metadata(metadatapath):
                 if k not in app:
                     app[k] = v
 
-    post_metadata_parse(app)
+    builds = []
+    for build in app.get('Builds', []):
+        builds.append(Build(build))
+    if builds:
+        app['Builds'] = builds
 
+    # if only .fdroid.yml was found, then this finds the appid
     if not app.id:
         if app.get('Builds'):
             build = app['Builds'][-1]
@@ -727,15 +693,18 @@ def parse_metadata(metadatapath):
     return app
 
 
-def parse_yaml_metadata(mf, app):
+def parse_yaml_metadata(mf):
     """Parse the .yml file and post-process it.
 
+    This function handles parsing a metadata YAML file and converting
+    all the various data types into a consistent internal
+    representation.  The results are meant to update an existing App
+    instance or used as a plain dict.
+
     Clean metadata .yml files can be used directly, but in order to
     make a better user experience for people editing .yml files, there
-    is post processing.  .fdroid.yml is embedded in the app's source
-    repo, so it is "user-generated".  That means that it can have
-    weird things in it that need to be removed so they don't break the
-    overall process.
+    is post processing.  That makes the parsing perform something like
+    Strict YAML.
 
     """
     try:
@@ -747,63 +716,129 @@ def parse_yaml_metadata(mf, app):
                            + common.run_yamllint(mf.name, indent=4),
                            cause=e)
 
+    if yamldata is None or yamldata == '':
+        yamldata = dict()
+    if not isinstance(yamldata, dict):
+        _warn_or_exception(
+            _("'{path}' has invalid format, it should be a dictionary!").format(
+                path=mf.name
+            )
+        )
+        logging.error(_('Using blank dictionary instead of contents of {path}!').format(
+            path=mf.name)
+        )
+        yamldata = dict()
+
     deprecated_in_yaml = ['Provides']
 
-    if yamldata:
-        for field in tuple(yamldata.keys()):
-            if field not in yaml_app_fields + deprecated_in_yaml:
-                msg = (_("Unrecognised app field '{fieldname}' in '{path}'")
-                       .format(fieldname=field, path=mf.name))
-                if Path(mf.name).name == '.fdroid.yml':
-                    logging.error(msg)
-                    del yamldata[field]
-                else:
-                    _warn_or_exception(msg)
+    for field in tuple(yamldata.keys()):
+        if field not in yaml_app_fields + deprecated_in_yaml:
+            msg = _("Unrecognised app field '{fieldname}' in '{path}'").format(
+                fieldname=field, path=mf.name
+            )
+            if Path(mf.name).name == '.fdroid.yml':
+                logging.error(msg)
+                del yamldata[field]
+            else:
+                _warn_or_exception(msg)
 
-        for deprecated_field in deprecated_in_yaml:
-            if deprecated_field in yamldata:
-                logging.warning(_("Ignoring '{field}' in '{metapath}' "
-                                  "metadata because it is deprecated.")
-                                .format(field=deprecated_field,
-                                        metapath=mf.name))
-                del yamldata[deprecated_field]
+    for deprecated_field in deprecated_in_yaml:
+        if deprecated_field in yamldata:
+            del yamldata[deprecated_field]
+            logging.warning(
+                _(
+                    "Ignoring '{field}' in '{metapath}' "
+                    "metadata because it is deprecated."
+                ).format(field=deprecated_field, metapath=mf.name)
+            )
 
-        if yamldata.get('Builds', None):
-            for build in yamldata.get('Builds', []):
-                # put all build flag keywords into a set to avoid
-                # excessive looping action
-                build_flag_set = set()
-                for build_flag in build.keys():
-                    build_flag_set.add(build_flag)
-                for build_flag in build_flag_set:
-                    if build_flag not in build_flags:
-                        _warn_or_exception(
-                            _("Unrecognised build flag '{build_flag}' "
-                              "in '{path}'").format(build_flag=build_flag,
-                                                    path=mf.name))
-        post_parse_yaml_metadata(yamldata)
-        app.update(yamldata)
-    return app
+    msg = _("Unrecognised build flag '{build_flag}' in '{path}'")
+    for build in yamldata.get('Builds', []):
+        for build_flag in build:
+            if build_flag not in build_flags:
+                _warn_or_exception(msg.format(build_flag=build_flag, path=mf.name))
+
+    post_parse_yaml_metadata(yamldata)
+    return yamldata
+
+
+def _normalize_type_string(v):
+    """Normalize any data to TYPE_STRING.
+
+    YAML 1.2's booleans are all lowercase.
+
+    Things like versionName are strings, but without quotes can be
+    numbers.  Like "versionName: 1.0" would be a YAML float, but
+    should be a string.
+
+    """
+    if isinstance(v, bool):
+        if v:
+            return 'true'
+        return 'false'
+    return str(v)
 
 
 def post_parse_yaml_metadata(yamldata):
-    """Transform yaml metadata to our internal data format."""
-    for build in yamldata.get('Builds', []):
-        for flag in build.keys():
-            _flagtype = flagtype(flag)
+    """Convert human-readable metadata data structures into consistent data structures.
 
-            if _flagtype is TYPE_SCRIPT:
-                if isinstance(build[flag], str):
-                    build[flag] = [build[flag]]
-            elif _flagtype is TYPE_STRING:
-                # things like versionNames are strings, but without quotes can be numbers
-                if isinstance(build[flag], float) or isinstance(build[flag], int):
-                    build[flag] = str(build[flag])
+    This also handles conversions that make metadata YAML behave
+    something like StrictYAML.  Specifically, a field should have a
+    fixed value type, regardless of YAML 1.2's type auto-detection.
+
+    """
+    for k, v in yamldata.items():
+        if fieldtype(k) == TYPE_LIST:
+            if isinstance(v, str):
+                yamldata[k] = [v, ]
+            elif v:
+                yamldata[k] = [str(i) for i in v]
+        elif fieldtype(k) == TYPE_INT:
+            if v:
+                yamldata[k] = int(v)
+        elif fieldtype(k) == TYPE_STRING:
+            if v or v == 0:
+                yamldata[k] = _normalize_type_string(v)
+        else:
+            if type(v) in (float, int):
+                yamldata[k] = str(v)
+
+    builds = []
+    for build in yamldata.get('Builds', []):
+        for k, v in build.items():
+            if v is None:
+                continue
+
+            _flagtype = flagtype(k)
+            if _flagtype is TYPE_STRING:
+                if v or v == 0:
+                    build[k] = _normalize_type_string(v)
             elif _flagtype is TYPE_INT:
+                build[k] = v
                 # versionCode must be int
-                if not isinstance(build[flag], int):
-                    _warn_or_exception(_('{build_flag} must be an integer, found: {value}')
-                                       .format(build_flag=flag, value=build[flag]))
+                if not isinstance(v, int):
+                    _warn_or_exception(
+                        _('{build_flag} must be an integer, found: {value}').format(
+                            build_flag=k, value=v
+                        )
+                    )
+            elif _flagtype in (TYPE_LIST, TYPE_SCRIPT):
+                if isinstance(v, str) or isinstance(v, int):
+                    build[k] = [_normalize_type_string(v)]
+                else:
+                    build[k] = v
+                # float and dict are here only to keep things compatible
+                if type(build[k]) not in (list, tuple, set, float, dict):
+                    _warn_or_exception(
+                        _('{build_flag} must be list or string, found: {value}').format(
+                            build_flag=k, value=v
+                        )
+                    )
+
+        builds.append(build)
+
+    if builds:
+        yamldata['Builds'] = sorted(builds, key=lambda build: build['versionCode'])
 
 
 def write_yaml(mf, app):
@@ -832,6 +867,7 @@ def write_yaml(mf, app):
     # suiteable version ruamel.yaml imported successfully
 
     def _field_to_yaml(typ, value):
+        """Convert data to YAML 1.2 format that keeps the right TYPE_*."""
         if typ is TYPE_STRING:
             return str(value)
         elif typ is TYPE_INT:
diff --git a/hooks/pre-commit b/hooks/pre-commit
index 4acfe2b5..8007a3e2 100755
--- a/hooks/pre-commit
+++ b/hooks/pre-commit
@@ -13,7 +13,7 @@ if [ -z "$files" ]; then
     SH_FILES="hooks/pre-commit"
     BASH_FILES="gradlew-fdroid jenkins-build-all jenkins-setup-build-environment jenkins-test completion/bash-completion buildserver/provision-*"
     RB_FILES="buildserver/Vagrantfile"
-    YML_FILES="buildserver/*.yml examples/*.yml"
+    YML_FILES=".*.yml .yamllint */*.yml */*.yaml"
 else
     # if actually committing right now, then only run on the files
     # that are going to be committed at this moment
@@ -36,7 +36,7 @@ else
             *.rb)
                 RB_FILES+=" $f"
                 ;;
-            *.yml)
+            *.yml|.*.yml|.yamllint)
                 YML_FILES+=" $f"
                 ;;
             *)
@@ -94,6 +94,7 @@ find_command() {
 }
 
 DASH=$(find_command dash)
+PYDOCSTYLE=$(find_command pydocstyle)
 PYFLAKES=$(find_command pyflakes)
 PEP8=$(find_command pycodestyle pep8)
 RUBY=$(find_command ruby)
@@ -103,6 +104,9 @@ if [ "$PY_FILES $PY_TEST_FILES" != " " ]; then
     if ! $PYFLAKES $PY_FILES $PY_TEST_FILES; then
 	err "pyflakes tests failed!"
     fi
+    if ! $PYDOCSTYLE $PY_FILES $PY_TEST_FILES; then
+	err "pydocstyle tests failed!"
+    fi
 fi
 
 if [ "$PY_FILES" != "" ]; then
@@ -139,7 +143,7 @@ for f in $RB_FILES; do
 done
 
 for f in $YML_FILES; do
-	if ! $YAMLLINT $f 1>/dev/null; then
+	if ! $YAMLLINT $f; then
 		err ".yml tests failed on $f!"
 	fi
 done
diff --git a/setup.py b/setup.py
index 065c1c28..72c592b2 100755
--- a/setup.py
+++ b/setup.py
@@ -10,15 +10,15 @@ from setuptools.command.install import install
 
 
 class VersionCheckCommand(Command):
-    """Make sure git tag and version match before uploading"""
+    """Make sure git tag and version match before uploading."""
 
     user_options = []
 
     def initialize_options(self):
-        """Abstract method that is required to be overwritten"""
+        """Abstract method that is required to be overwritten."""
 
     def finalize_options(self):
-        """Abstract method that is required to be overwritten"""
+        """Abstract method that is required to be overwritten."""
 
     def run(self):
         version = self.distribution.get_version()
diff --git a/tests/import_subcommand.TestCase b/tests/import_subcommand.TestCase
index cd11775e..eb41ae20 100755
--- a/tests/import_subcommand.TestCase
+++ b/tests/import_subcommand.TestCase
@@ -2,17 +2,20 @@
 
 # http://www.drdobbs.com/testing/unit-testing-with-python/240165163
 
+import git
 import logging
 import optparse
+import os
 import shutil
 import sys
 import tempfile
 import unittest
+import yaml
 from unittest import mock
 from pathlib import Path
 
 import requests
-from testcommon import TmpCwd
+from testcommon import TmpCwd, mkdtemp
 
 localmodule = Path(__file__).resolve().parent.parent
 print('localmodule: ' + str(localmodule))
@@ -22,6 +25,7 @@ if localmodule not in sys.path:
 import fdroidserver.common
 import fdroidserver.import_subcommand
 import fdroidserver.metadata
+from fdroidserver.exception import FDroidException
 
 
 class ImportTest(unittest.TestCase):
@@ -32,6 +36,13 @@ class ImportTest(unittest.TestCase):
         self.basedir = localmodule / 'tests'
         fdroidserver.import_subcommand.options = mock.Mock()
         fdroidserver.import_subcommand.options.rev = None
+        os.chdir(self.basedir)
+        self._td = mkdtemp()
+        self.testdir = self._td.name
+
+    def tearDown(self):
+        os.chdir(self.basedir)
+        self._td.cleanup()
 
     def test_import_gitlab(self):
         with tempfile.TemporaryDirectory() as testdir, TmpCwd(testdir):
@@ -122,6 +133,32 @@ class ImportTest(unittest.TestCase):
             with self.assertRaises(ValueError):
                 fdroidserver.import_subcommand.get_app_from_url(url)
 
+    @mock.patch('sys.argv', ['fdroid import', '-u', 'https://example.com/mystery/url'])
+    @mock.patch('fdroidserver.import_subcommand.clone_to_tmp_dir', lambda a: None)
+    def test_unrecognized_url(self):
+        """Test whether error is thrown when the RepoType was not found.
+
+        clone_to_tmp_dir is mocked out to prevent this test from using
+        the network, if it gets past the code that throws the error.
+
+        """
+        with self.assertRaises(FDroidException):
+            fdroidserver.import_subcommand.main()
+
+    @mock.patch('sys.argv', ['fdroid import', '-u', 'https://fake/git/url.git'])
+    @mock.patch('fdroidserver.import_subcommand.clone_to_tmp_dir', lambda a: Path('td'))
+    def test_main_local_git(self):
+        os.chdir(self.testdir)
+        git.Repo.init('td')
+        with Path('td/build.gradle').open('w') as fp:
+            fp.write('android { defaultConfig { applicationId "com.example" } }')
+        fdroidserver.import_subcommand.main()
+        with open('metadata/com.example.yml') as fp:
+            data = yaml.safe_load(fp)
+        self.assertEqual(data['Repo'], sys.argv[2])
+        self.assertEqual(data['RepoType'], 'git')
+        self.assertEqual(1, len(data['Builds']))
+
 
 if __name__ == "__main__":
     parser = optparse.OptionParser()
diff --git a/tests/metadata.TestCase b/tests/metadata.TestCase
index 6b2a94b4..b340038b 100755
--- a/tests/metadata.TestCase
+++ b/tests/metadata.TestCase
@@ -1,5 +1,6 @@
 #!/usr/bin/env python3
 
+import copy
 import io
 import logging
 import optparse
@@ -26,9 +27,8 @@ print('localmodule: ' + str(localmodule))
 if localmodule not in sys.path:
     sys.path.insert(0, str(localmodule))
 
-
-import fdroidserver.common
-import fdroidserver.metadata
+import fdroidserver
+from fdroidserver import metadata
 from fdroidserver.exception import MetaDataException
 
 
@@ -288,6 +288,18 @@ class MetadataTest(unittest.TestCase):
                 (Path('metadata-rewrite-yml') / file_name).read_text(encoding='utf-8'),
             )
 
+    def test_normalize_type_string(self):
+        """TYPE_STRING currently has some quirky behavior."""
+        self.assertEqual('123456', metadata._normalize_type_string(123456))
+        self.assertEqual('1.0', metadata._normalize_type_string(1.0))
+        self.assertEqual('0', metadata._normalize_type_string(0))
+        self.assertEqual('0.0', metadata._normalize_type_string(0.0))
+        self.assertEqual('0.1', metadata._normalize_type_string(0.1))
+        self.assertEqual('[]', metadata._normalize_type_string(list()))
+        self.assertEqual('{}', metadata._normalize_type_string(dict()))
+        self.assertEqual('false', metadata._normalize_type_string(False))
+        self.assertEqual('true', metadata._normalize_type_string(True))
+
     def test_post_parse_yaml_metadata(self):
         fdroidserver.metadata.warnings_action = 'error'
         yamldata = OrderedDict()
@@ -362,6 +374,21 @@ class MetadataTest(unittest.TestCase):
                 allappids.append(appid)
             self.assertEqual(randomlist, allappids)
 
+    def test_parse_yaml_metadata_0size_file(self):
+        mf = io.StringIO('')
+        mf.name = 'mock_filename.yaml'
+        self.assertEqual(fdroidserver.metadata.parse_yaml_metadata(mf), dict())
+
+    def test_parse_yaml_metadata_empty_dict_file(self):
+        mf = io.StringIO('{}')
+        mf.name = 'mock_filename.yaml'
+        self.assertEqual(fdroidserver.metadata.parse_yaml_metadata(mf), dict())
+
+    def test_parse_yaml_metadata_empty_string_file(self):
+        mf = io.StringIO('""')
+        mf.name = 'mock_filename.yaml'
+        self.assertEqual(fdroidserver.metadata.parse_yaml_metadata(mf), dict())
+
     def test_parse_yaml_metadata_unknown_app_field(self):
         mf = io.StringIO(
             textwrap.dedent(
@@ -375,7 +402,7 @@ class MetadataTest(unittest.TestCase):
         mf.name = 'mock_filename.yaml'
         with mock.patch('fdroidserver.metadata.warnings_action', 'error'):
             with self.assertRaises(MetaDataException):
-                fdroidserver.metadata.parse_yaml_metadata(mf, {})
+                fdroidserver.metadata.parse_yaml_metadata(mf)
 
     def test_parse_yaml_metadata_unknown_build_flag(self):
         mf = io.StringIO(
@@ -390,7 +417,23 @@ class MetadataTest(unittest.TestCase):
         mf.name = 'mock_filename.yaml'
         with mock.patch('fdroidserver.metadata.warnings_action', 'error'):
             with self.assertRaises(MetaDataException):
-                fdroidserver.metadata.parse_yaml_metadata(mf, {})
+                fdroidserver.metadata.parse_yaml_metadata(mf)
+
+    def test_parse_yaml_metadata_continue_on_warning(self):
+        """When errors are disabled, parsing should provide something that can work.
+
+        When errors are disabled, then it should try to give data that
+        lets something happen.  A zero-length file is valid for
+        operation, it just declares a Application ID as "known" and
+        nothing else.  This example gives a list as the base in the
+        .yml file, which is unparsable, so it gives a warning message
+        and carries on with a blank dict.
+
+        """
+        fdroidserver.metadata.warnings_action = None
+        mf = io.StringIO('[AntiFeatures: Tracking]')
+        mf.name = 'mock_filename.yaml'
+        self.assertEqual(fdroidserver.metadata.parse_yaml_metadata(mf), dict())
 
     def test_parse_yaml_srclib_corrupt_file(self):
         with tempfile.TemporaryDirectory() as testdir:
@@ -487,9 +530,8 @@ class MetadataTest(unittest.TestCase):
         )
         mf.name = 'mock_filename.yaml'
         mf.seek(0)
-        result = {}
         with mock.patch('fdroidserver.metadata.warnings_action', 'error'):
-            fdroidserver.metadata.parse_yaml_metadata(mf, result)
+            result = fdroidserver.metadata.parse_yaml_metadata(mf)
         self.maxDiff = None
         self.assertDictEqual(
             result,
@@ -543,9 +585,8 @@ class MetadataTest(unittest.TestCase):
         )
         mf.name = 'mock_filename.yaml'
         mf.seek(0)
-        result = {}
         with mock.patch('fdroidserver.metadata.warnings_action', 'error'):
-            fdroidserver.metadata.parse_yaml_metadata(mf, result)
+            result = fdroidserver.metadata.parse_yaml_metadata(mf)
         self.maxDiff = None
         self.assertDictEqual(
             result,
@@ -594,9 +635,8 @@ class MetadataTest(unittest.TestCase):
         )
         mf.name = 'mock_filename.yaml'
         mf.seek(0)
-        result = {}
         with mock.patch('fdroidserver.metadata.warnings_action', 'error'):
-            fdroidserver.metadata.parse_yaml_metadata(mf, result)
+            result = fdroidserver.metadata.parse_yaml_metadata(mf)
         self.assertDictEqual(
             result,
             {
@@ -629,9 +669,8 @@ class MetadataTest(unittest.TestCase):
         )
         mf.name = 'mock_filename.yaml'
         mf.seek(0)
-        result = {}
         with mock.patch('fdroidserver.metadata.warnings_action', 'error'):
-            fdroidserver.metadata.parse_yaml_metadata(mf, result)
+            result = fdroidserver.metadata.parse_yaml_metadata(mf)
             self.assertNotIn('Provides', result)
             self.assertNotIn('provides', result)
 
@@ -1151,6 +1190,223 @@ class MetadataTest(unittest.TestCase):
             build.ndk_path()
 
 
+class PostMetadataParseTest(unittest.TestCase):
+    """Test the functions that post process the YAML input.
+
+    The following series of "post_metadata_parse" tests map out the
+    current state of automatic type conversion in the YAML post
+    processing.  They are not necessary a statement of how things
+    should be, but more to surface the details of it functions.
+
+    """
+
+    def setUp(self):
+        fdroidserver.metadata.warnings_action = 'error'
+
+    def _post_metadata_parse_app_list(self, from_yaml, expected):
+        app = {'AntiFeatures': from_yaml}
+        metadata.post_parse_yaml_metadata(app)
+        return {'AntiFeatures': expected}, app
+
+    def _post_metadata_parse_app_string(self, from_yaml, expected):
+        app = {'Repo': from_yaml}
+        metadata.post_parse_yaml_metadata(app)
+        return {'Repo': expected}, app
+
+    def _post_metadata_parse_build_bool(self, from_yaml, expected):
+        tested_key = 'submodules'
+        app = {'Builds': [{'versionCode': 1, tested_key: from_yaml}]}
+        post = copy.deepcopy(app)
+        metadata.post_parse_yaml_metadata(post)
+        del app['Builds'][0]['versionCode']
+        del post['Builds'][0]['versionCode']
+        for build in post['Builds']:
+            for k in list(build):
+                if k != tested_key:
+                    del build[k]
+        app['Builds'][0][tested_key] = expected
+        return app, post
+
+    def _post_metadata_parse_build_int(self, from_yaml, expected):
+        tested_key = 'versionCode'
+        app = {'Builds': [{'versionCode': from_yaml}]}
+        post = copy.deepcopy(app)
+        metadata.post_parse_yaml_metadata(post)
+        for build in post['Builds']:
+            for k in list(build):
+                if k != tested_key:
+                    del build[k]
+        app['Builds'][0][tested_key] = expected
+        return app, post
+
+    def _post_metadata_parse_build_list(self, from_yaml, expected):
+        tested_key = 'rm'
+        app = {'Builds': [{'versionCode': 1, tested_key: from_yaml}]}
+        post = copy.deepcopy(app)
+        metadata.post_parse_yaml_metadata(post)
+        del app['Builds'][0]['versionCode']
+        del post['Builds'][0]['versionCode']
+        for build in post['Builds']:
+            for k in list(build):
+                if k != tested_key:
+                    del build[k]
+        app['Builds'][0][tested_key] = expected
+        return app, post
+
+    def _post_metadata_parse_build_script(self, from_yaml, expected):
+        tested_key = 'build'
+        app = {'Builds': [{'versionCode': 1, tested_key: from_yaml}]}
+        post = copy.deepcopy(app)
+        metadata.post_parse_yaml_metadata(post)
+        del app['Builds'][0]['versionCode']
+        del post['Builds'][0]['versionCode']
+        for build in post['Builds']:
+            for k in list(build):
+                if k != tested_key:
+                    del build[k]
+        app['Builds'][0][tested_key] = expected
+        return app, post
+
+    def _post_metadata_parse_build_string(self, from_yaml, expected):
+        tested_key = 'commit'
+        app = {'Builds': [{'versionCode': 1, tested_key: from_yaml}]}
+        post = copy.deepcopy(app)
+        metadata.post_parse_yaml_metadata(post)
+        del app['Builds'][0]['versionCode']
+        del post['Builds'][0]['versionCode']
+        for build in post['Builds']:
+            for k in list(build):
+                if k != tested_key:
+                    del build[k]
+        app['Builds'][0][tested_key] = expected
+        return app, post
+
+    def test_post_metadata_parse_int(self):
+        """Run the int 123456 through the various field and flag types."""
+        with self.assertRaises(TypeError):
+            self._post_metadata_parse_app_list(123456, TypeError)
+        self.assertEqual(*self._post_metadata_parse_app_string(123456, '123456'))
+        self.assertEqual(*self._post_metadata_parse_build_bool(123456, 123456))
+        self.assertEqual(*self._post_metadata_parse_build_int(123456, 123456))
+        self.assertEqual(*self._post_metadata_parse_build_list(123456, ['123456']))
+        self.assertEqual(*self._post_metadata_parse_build_script(123456, ['123456']))
+        self.assertEqual(*self._post_metadata_parse_build_string(123456, '123456'))
+
+    def test_post_metadata_parse_int_0(self):
+        """Run the int 0 through the various field and flag types."""
+        self.assertEqual(*self._post_metadata_parse_app_list(0, 0))
+        self.assertEqual(*self._post_metadata_parse_app_string(0, '0'))
+        self.assertEqual(*self._post_metadata_parse_build_bool(0, 0))
+        self.assertEqual(*self._post_metadata_parse_build_int(0, 0))
+        self.assertEqual(*self._post_metadata_parse_build_list(0, ['0']))
+        self.assertEqual(*self._post_metadata_parse_build_script(0, ['0']))
+        self.assertEqual(*self._post_metadata_parse_build_string(0, '0'))
+
+    def test_post_metadata_parse_float_0_0(self):
+        """Run the float 0.0 through the various field and flag types."""
+        self.assertEqual(*self._post_metadata_parse_app_list(0.0, 0.0))
+        self.assertEqual(*self._post_metadata_parse_app_string(0.0, '0.0'))
+        self.assertEqual(*self._post_metadata_parse_build_bool(0.0, 0.0))
+        with self.assertRaises(MetaDataException):
+            self._post_metadata_parse_build_int(0.0, MetaDataException)
+        self.assertEqual(*self._post_metadata_parse_build_list(0.0, 0.0))
+        self.assertEqual(*self._post_metadata_parse_build_script(0.0, 0.0))
+        self.assertEqual(*self._post_metadata_parse_build_string(0.0, '0.0'))
+
+    def test_post_metadata_parse_float_0_1(self):
+        """Run the float 0.1 through the various field and flag types."""
+        with self.assertRaises(TypeError):
+            self._post_metadata_parse_app_list(0.1, TypeError)
+        self.assertEqual(*self._post_metadata_parse_app_string(0.1, '0.1'))
+        self.assertEqual(*self._post_metadata_parse_build_bool(0.1, 0.1))
+        with self.assertRaises(MetaDataException):
+            self._post_metadata_parse_build_int(0.1, MetaDataException)
+        self.assertEqual(*self._post_metadata_parse_build_list(0.1, 0.1))
+        self.assertEqual(*self._post_metadata_parse_build_script(0.1, 0.1))
+        self.assertEqual(*self._post_metadata_parse_build_string(0.1, '0.1'))
+
+    def test_post_metadata_parse_float_1_0(self):
+        """Run the float 1.0 through the various field and flag types."""
+        with self.assertRaises(TypeError):
+            self._post_metadata_parse_app_list(1.0, TypeError)
+        self.assertEqual(*self._post_metadata_parse_app_string(1.0, '1.0'))
+        self.assertEqual(*self._post_metadata_parse_build_bool(1.0, 1.0))
+        with self.assertRaises(MetaDataException):
+            self._post_metadata_parse_build_int(1.0, MetaDataException)
+        self.assertEqual(*self._post_metadata_parse_build_list(1.0, 1.0))
+        self.assertEqual(*self._post_metadata_parse_build_script(1.0, 1.0))
+        self.assertEqual(*self._post_metadata_parse_build_string(1.0, '1.0'))
+
+    def test_post_metadata_parse_empty_list(self):
+        self.assertEqual(*self._post_metadata_parse_app_list(list(), list()))
+        self.assertEqual(*self._post_metadata_parse_app_string(list(), list()))
+        self.assertEqual(*self._post_metadata_parse_build_bool(list(), list()))
+        with self.assertRaises(MetaDataException):
+            self._post_metadata_parse_build_int(list(), MetaDataException)
+        self.assertEqual(*self._post_metadata_parse_build_list(list(), list()))
+        self.assertEqual(*self._post_metadata_parse_build_script(list(), list()))
+        self.assertEqual(*self._post_metadata_parse_build_string(list(), list()))
+
+    def test_post_metadata_parse_set_of_1(self):
+        self.assertEqual(*self._post_metadata_parse_app_list({1}, ['1']))
+        self.assertEqual(*self._post_metadata_parse_app_string({1}, '{1}'))
+        self.assertEqual(*self._post_metadata_parse_build_bool({1}, {1}))
+        with self.assertRaises(MetaDataException):
+            self._post_metadata_parse_build_int({1}, MetaDataException)
+        self.assertEqual(*self._post_metadata_parse_build_list({1}, {1}))
+        self.assertEqual(*self._post_metadata_parse_build_script({1}, {1}))
+        self.assertEqual(*self._post_metadata_parse_build_string({1}, '{1}'))
+
+    def test_post_metadata_parse_empty_dict(self):
+        self.assertEqual(*self._post_metadata_parse_app_list(dict(), dict()))
+        self.assertEqual(*self._post_metadata_parse_app_string(dict(), dict()))
+        self.assertEqual(*self._post_metadata_parse_build_bool(dict(), dict()))
+        with self.assertRaises(MetaDataException):
+            self._post_metadata_parse_build_int(dict(), MetaDataException)
+        self.assertEqual(*self._post_metadata_parse_build_list(dict(), dict()))
+        self.assertEqual(*self._post_metadata_parse_build_script(dict(), dict()))
+        self.assertEqual(*self._post_metadata_parse_build_string(dict(), dict()))
+
+    def test_post_metadata_parse_list_int_string(self):
+        self.assertEqual(*self._post_metadata_parse_app_list([1, 'a'], ['1', 'a']))
+        self.assertEqual(*self._post_metadata_parse_app_string([1, 'a'], "[1, 'a']"))
+        self.assertEqual(*self._post_metadata_parse_build_bool([1, 'a'], [1, 'a']))
+        with self.assertRaises(MetaDataException):
+            self._post_metadata_parse_build_int([1, 'a'], MetaDataException)
+        self.assertEqual(*self._post_metadata_parse_build_list([1, 'a'], [1, 'a']))
+        self.assertEqual(*self._post_metadata_parse_build_script([1, 'a'], [1, 'a']))
+        self.assertEqual(*self._post_metadata_parse_build_string([1, 'a'], "[1, 'a']"))
+
+    def test_post_metadata_parse_dict_int_string(self):
+        self.assertEqual(*self._post_metadata_parse_app_list({'k': 1}, ['k']))
+        self.assertEqual(*self._post_metadata_parse_app_string({'k': 1}, "{'k': 1}"))
+        self.assertEqual(*self._post_metadata_parse_build_bool({'k': 1}, {'k': 1}))
+        with self.assertRaises(MetaDataException):
+            self._post_metadata_parse_build_int({'k': 1}, MetaDataException)
+        self.assertEqual(*self._post_metadata_parse_build_list({'k': 1}, {'k': 1}))
+        self.assertEqual(*self._post_metadata_parse_build_script({'k': 1}, {'k': 1}))
+        self.assertEqual(*self._post_metadata_parse_build_string({'k': 1}, "{'k': 1}"))
+
+    def test_post_metadata_parse_false(self):
+        self.assertEqual(*self._post_metadata_parse_app_list(False, False))
+        self.assertEqual(*self._post_metadata_parse_app_string(False, 'false'))
+        self.assertEqual(*self._post_metadata_parse_build_bool(False, False))
+        self.assertEqual(*self._post_metadata_parse_build_int(False, False))
+        self.assertEqual(*self._post_metadata_parse_build_list(False, ['false']))
+        self.assertEqual(*self._post_metadata_parse_build_script(False, ['false']))
+        self.assertEqual(*self._post_metadata_parse_build_string(False, 'false'))
+
+    def test_post_metadata_parse_true(self):
+        with self.assertRaises(TypeError):
+            self._post_metadata_parse_app_list(True, TypeError)
+        self.assertEqual(*self._post_metadata_parse_app_string(True, 'true'))
+        self.assertEqual(*self._post_metadata_parse_build_bool(True, True))
+        self.assertEqual(*self._post_metadata_parse_build_int(True, True))
+        self.assertEqual(*self._post_metadata_parse_build_list(True, ['true']))
+        self.assertEqual(*self._post_metadata_parse_build_script(True, ['true']))
+        self.assertEqual(*self._post_metadata_parse_build_string(True, 'true'))
+
+
 if __name__ == "__main__":
     parser = optparse.OptionParser()
     parser.add_option(
@@ -1164,4 +1420,4 @@ if __name__ == "__main__":
 
     newSuite = unittest.TestSuite()
     newSuite.addTest(unittest.makeSuite(MetadataTest))
-    unittest.main(failfast=True)
+    unittest.main(failfast=False)
diff --git a/tests/metadata/dump/com.politedroid.yaml b/tests/metadata/dump/com.politedroid.yaml
index 4f4be52b..acde9299 100644
--- a/tests/metadata/dump/com.politedroid.yaml
+++ b/tests/metadata/dump/com.politedroid.yaml
@@ -185,7 +185,6 @@ UpdateCheckName: null
 VercodeOperation: []
 WebSite: ''
 added: null
-comments: {}
 id: com.politedroid
 lastUpdated: null
 metadatapath: metadata/com.politedroid.yml
diff --git a/tests/metadata/dump/org.adaway.yaml b/tests/metadata/dump/org.adaway.yaml
index 0428721c..57fab70c 100644
--- a/tests/metadata/dump/org.adaway.yaml
+++ b/tests/metadata/dump/org.adaway.yaml
@@ -1136,7 +1136,6 @@ UpdateCheckName: null
 VercodeOperation: []
 WebSite: http://sufficientlysecure.org/index.php/adaway
 added: null
-comments: {}
 id: org.adaway
 lastUpdated: null
 metadatapath: metadata/org.adaway.yml
diff --git a/tests/metadata/dump/org.smssecure.smssecure.yaml b/tests/metadata/dump/org.smssecure.smssecure.yaml
index 1637ad5a..a88a6a6a 100644
--- a/tests/metadata/dump/org.smssecure.smssecure.yaml
+++ b/tests/metadata/dump/org.smssecure.smssecure.yaml
@@ -406,7 +406,6 @@ UpdateCheckName: null
 VercodeOperation: []
 WebSite: http://www.smssecure.org
 added: null
-comments: {}
 id: org.smssecure.smssecure
 lastUpdated: null
 metadatapath: metadata/org.smssecure.smssecure.yml
diff --git a/tests/metadata/dump/org.videolan.vlc.yaml b/tests/metadata/dump/org.videolan.vlc.yaml
index 42620442..290dbabe 100644
--- a/tests/metadata/dump/org.videolan.vlc.yaml
+++ b/tests/metadata/dump/org.videolan.vlc.yaml
@@ -2643,7 +2643,6 @@ VercodeOperation:
   - '%c + 5'
 WebSite: http://www.videolan.org/vlc/download-android.html
 added: null
-comments: {}
 id: org.videolan.vlc
 lastUpdated: null
 metadatapath: metadata/org.videolan.vlc.yml