Make -r letters "s" and "S" aliases

Similar reasons as the previous commit

src/_pytest/terminal.py

@@ -172,10 +172,11 @@ def getreportopt(config: Config) -> str:
         reportchars += "w"
     elif config.option.disable_warnings and "w" in reportchars:
         reportchars = reportchars.replace("w", "")
+    aliases = {"F", "S"}
     for char in reportchars:
-        # f and F are aliases
-        if char == "F":
-            char = "f"
+        # handle old aliases
+        if char in aliases:
+            char = char.lower()
         if char == "a":
             reportopts = "sxXwEf"
         elif char == "A":
@@ -989,7 +990,6 @@ class TerminalReporter:
             "X": show_xpassed,
             "f": partial(show_simple, "failed"),
             "s": show_skipped,
-            "S": show_skipped,
             "p": partial(show_simple, "passed"),
             "E": partial(show_simple, "error"),
         }  # type: Mapping[str, Callable[[List[str]], None]]

testing/test_terminal.py

@@ -755,6 +755,7 @@ class TestTerminalFunctional:
         result.stdout.fnmatch_lines(["collected 3 items", "hello from hook: 3 items"])
 
     def test_summary_f_alias(self, testdir):
+        """Test that 'f' and 'F' report chars are aliases and don't show up twice in the summary (#6334)"""
         testdir.makepyfile(
             """
             def test():
@@ -766,6 +767,22 @@ class TestTerminalFunctional:
         result.stdout.fnmatch_lines([expected])
         assert result.stdout.lines.count(expected) == 1
 
+    def test_summary_s_alias(self, testdir):
+        """Test that 's' and 'S' report chars are aliases and don't show up twice in the summary"""
+        testdir.makepyfile(
+            """
+            import pytest
+
+            @pytest.mark.skip
+            def test():
+                pass
+            """
+        )
+        result = testdir.runpytest("-rsS")
+        expected = "SKIPPED [1] test_summary_s_alias.py:3: unconditional skip"
+        result.stdout.fnmatch_lines([expected])
+        assert result.stdout.lines.count(expected) == 1
+
 
 def test_fail_extra_reporting(testdir, monkeypatch):
     monkeypatch.setenv("COLUMNS", "80")