automatically bump pkgrel on version duplicates

The new --(no-)increment flag has been added to add, update and rebuild
subcommands. In case if it is true and package version is the same as in
repository, it will automatically bump pkgrel appending (increasing)
minor part of it (e.g. 1.0.0-1 -> 1.0.0-1.1).

Inn order to implement this, the shadow (e.g. it will not store it in
database) patch for pkgrel will be created

tests/ahriman/core/test_util.py

@@ -8,12 +8,12 @@ import subprocess
 from pathlib import Path
 from pytest_mock import MockerFixture
 from typing import Any
-from unittest.mock import MagicMock
+from unittest.mock import MagicMock, call as MockCall
 
 from ahriman.core.exceptions import BuildError, OptionError, UnsafeRunError
 from ahriman.core.util import check_output, check_user, dataclass_view, enum_values, exception_response_text, \
-    extract_user, filter_json, full_version, package_like, partition, pretty_datetime, pretty_size, safe_filename, \
-    srcinfo_property, srcinfo_property_list, trim_package, utcnow, walk
+    extract_user, filter_json, full_version, package_like, parse_version, partition, pretty_datetime, pretty_size, \
+    safe_filename, srcinfo_property, srcinfo_property_list, trim_package, utcnow, walk
 from ahriman.models.package import Package
 from ahriman.models.package_source import PackageSource
 from ahriman.models.repository_paths import RepositoryPaths
@@ -128,6 +128,15 @@ def test_check_output_failure_exception(mocker: MockerFixture) -> None:
         check_output("echo", "hello", exception=exception, logger=logging.getLogger(""))
 
 
+def test_check_output_empty_line(mocker: MockerFixture) -> None:
+    """
+    must correctly process empty lines in command output
+    """
+    logger_mock = mocker.patch("logging.Logger.debug")
+    assert check_output("python", "-c", """print(); print("hello")""", logger=logging.getLogger("")) == "\nhello"
+    logger_mock.assert_has_calls([MockCall(""), MockCall("hello")])
+
+
 def test_check_user(mocker: MockerFixture) -> None:
     """
     must check user correctly
@@ -273,6 +282,17 @@ def test_package_like_sig(package_ahriman: Package) -> None:
     assert not package_like(sig_file)
 
 
+def test_parse_version() -> None:
+    """
+    must correctly parse version into components
+    """
+    assert parse_version("1.2.3-4") == (None, "1.2.3", "4")
+    assert parse_version("5:1.2.3-4") == ("5", "1.2.3", "4")
+    assert parse_version("1.2.3-4.2") == (None, "1.2.3", "4.2")
+    assert parse_version("0:1.2.3-4.2") == ("0", "1.2.3", "4.2")
+    assert parse_version("0:1.2.3-4") == ("0", "1.2.3", "4")
+
+
 def test_partition() -> None:
     """
     must partition list based on predicate