Don't take . folder into consideration for tools.files.copy() `ex…

…cludes` patterns (#15349)

* Don't take . folder into consideration for tools.copy excludes patterns

* Simplify testing following review suggestion

conan/tools/files/copy_pattern.py

@@ -69,11 +69,13 @@ def _filter_files(src, pattern, excludes, ignore_case, excluded_folder):
 
         relative_path = os.path.relpath(root, src)
         compare_relative_path = relative_path.lower() if ignore_case else relative_path
-        for exclude in excludes:
-            if fnmatch.fnmatch(compare_relative_path, exclude):
-                subfolders[:] = []
-                files = []
-                break
+        # Don't try to exclude the start folder, it conflicts with excluding names starting with dots
+        if not compare_relative_path == ".":
+            for exclude in excludes:
+                if fnmatch.fnmatch(compare_relative_path, exclude):
+                    subfolders[:] = []
+                    files = []
+                    break
         for f in files:
             relative_name = os.path.normpath(os.path.join(relative_path, f))
             filenames.append(relative_name)

conans/test/unittests/tools/files/test_tool_copy.py

@@ -7,7 +7,7 @@
 
 from conan.tools.files import copy
 from conans.test.utils.test_files import temp_folder
-from conans.util.files import load, save, mkdir
+from conans.util.files import load, save, mkdir, save_files
 
 
 class ToolCopyTest(unittest.TestCase):
@@ -161,6 +161,7 @@ def test_excludes(self):
         save(os.path.join(folder1, "MyLib.txt"), "")
         save(os.path.join(folder1, "MyLibImpl.txt"), "")
         save(os.path.join(folder1, "MyLibTests.txt"), "")
+
         folder2 = temp_folder()
         copy(None, "*.txt", folder1, folder2, excludes="*Test*.txt")
         self.assertEqual({'MyLib.txt', 'MyLibImpl.txt'}, set(os.listdir(folder2)))
@@ -169,6 +170,24 @@ def test_excludes(self):
         copy(None, "*.txt", folder1, folder2, excludes=("*Test*.txt", "*Impl*"))
         self.assertEqual(['MyLib.txt'], os.listdir(folder2))
 
+    def test_excludes_hidden_files(self):
+        folder1 = temp_folder()
+        save_files(folder1, {
+            "file1.txt": "",
+            ".hiddenfile": "",
+            "foo/file2.txt": "",
+            "foo/.hiddenfile2": "",
+            ".hiddenfolder/file3.txt": "",
+            "foo/bar/file4.txt": ""
+        })
+
+        folder2 = temp_folder()
+        copy(None, "*", folder1, folder2, excludes=(".*", "*/.*"))
+        assert os.listdir(folder2) == ['file1.txt', 'foo']
+        assert os.listdir(os.path.join(folder2, "foo")) == ['file2.txt', 'bar']
+        assert not os.path.exists(os.path.join(folder2, ".hiddenfolder"))
+        assert os.listdir(os.path.join(folder2, "foo", "bar")) == ['file4.txt']
+
     def test_excludes_camelcase_folder(self):
         # https://github.com/conan-io/conan/issues/8153
         folder1 = temp_folder()