color: fix have_fg not re assign to true

In method _parse the value of this variable 'have_fg ' is always
False, Maybe reassign it to True is lost.
I guess the author’s original intention was:
if set some value in gitconfig file(for ex: text = black red ul),
the first is bg color, the second is fg color, and the last one is attr.



Change-Id: I372698fe625db4c1fdaa94ea7f193a80a850ecb9
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/425997
Reviewed-by: Mike Frysinger <vapier@google.com>
Tested-by: Bright Ma <mmh1989@foxmail.com>
Commit-Queue: Josip Sokcevic <sokcevic@google.com>

color.py

@@ -210,6 +210,7 @@ class Coloring:
                 if have_fg:
                     bg = a
                 else:
+                    have_fg = True
                     fg = a
             elif is_attr(a):
                 attr = a

tests/fixtures/test.gitconfig

@@ -11,3 +11,11 @@
 	intk = 10k
 	intm = 10m
 	intg = 10g
+
+[color "status"]
+	one = yellow
+	two = magenta cyan
+	three = black red ul
+	reset = reset
+	none
+	empty =

tests/test_color.py

@@ -0,0 +1,74 @@
+# Copyright (C) 2024 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Unittests for the color.py module."""
+
+import os
+import unittest
+
+import color
+import git_config
+
+
+def fixture(*paths):
+    """Return a path relative to test/fixtures."""
+    return os.path.join(os.path.dirname(__file__), "fixtures", *paths)
+
+
+class ColoringTests(unittest.TestCase):
+    """tests of the Coloring class."""
+
+    def setUp(self):
+        """Create a GitConfig object using the test.gitconfig fixture."""
+        config_fixture = fixture("test.gitconfig")
+        self.config = git_config.GitConfig(config_fixture)
+        color.SetDefaultColoring("true")
+        self.color = color.Coloring(self.config, "status")
+
+    def test_Color_Parse_all_params_none(self):
+        """all params are None"""
+        val = self.color._parse(None, None, None, None)
+        self.assertEqual("", val)
+
+    def test_Color_Parse_first_parameter_none(self):
+        """check fg & bg & attr"""
+        val = self.color._parse(None, "black", "red", "ul")
+        self.assertEqual("\x1b[4;30;41m", val)
+
+    def test_Color_Parse_one_entry(self):
+        """check fg"""
+        val = self.color._parse("one", None, None, None)
+        self.assertEqual("\033[33m", val)
+
+    def test_Color_Parse_two_entry(self):
+        """check fg & bg"""
+        val = self.color._parse("two", None, None, None)
+        self.assertEqual("\033[35;46m", val)
+
+    def test_Color_Parse_three_entry(self):
+        """check fg & bg & attr"""
+        val = self.color._parse("three", None, None, None)
+        self.assertEqual("\033[4;30;41m", val)
+
+    def test_Color_Parse_reset_entry(self):
+        """check reset entry"""
+        val = self.color._parse("reset", None, None, None)
+        self.assertEqual("\033[m", val)
+
+    def test_Color_Parse_empty_entry(self):
+        """check empty entry"""
+        val = self.color._parse("none", "blue", "white", "dim")
+        self.assertEqual("\033[2;34;47m", val)
+        val = self.color._parse("empty", "green", "white", "bold")
+        self.assertEqual("\033[1;32;47m", val)