Preserve blank lines in option help text

AUTHORS

@@ -366,6 +366,7 @@ Nico Vidal
 Nikesh Chavhan
 Nikolay Kondratyev
 Nipunn Koorapati
+niukanen1
 Oleg Pidsadnyi
 Oleg Sushchenko
 Oleksandr Zavertniev

changelog/15021.bugfix.rst

@@ -0,0 +1 @@
+Preserved blank lines between paragraphs in command-line option help text.

src/_pytest/config/argparsing.py

@@ -574,7 +574,7 @@ def _split_lines(self, text: str, width: int) -> list[str]:
         """
         lines = []
         for line in text.splitlines():
-            lines.extend(textwrap.wrap(line.strip(), width))
+            lines.extend(textwrap.wrap(line.strip(), width) or [""])
         return lines
 
 

testing/test_parseopt.py

@@ -286,6 +286,31 @@ def test_drop_short_help0(self, parser: parseopt.Parser) -> None:
         help = parser.optparser.format_help()
         assert "--func-args, --doit  foo" in help
 
+    def test_help_preserves_blank_lines(self, parser: parseopt.Parser) -> None:
+        parser.addoption(
+            "--paragraph-help",
+            action="store_true",
+            help="first paragraph\n\nsecond paragraph",
+        )
+
+        lines = parser.optparser.format_help().splitlines()
+        first_line = next(
+            i for i, line in enumerate(lines) if "first paragraph" in line
+        )
+
+        assert lines[first_line + 1].strip() == ""
+        assert lines[first_line + 2].strip() == "second paragraph"
+
+    def test_help_line_wrapping_with_blank_lines(self) -> None:
+        formatter = parseopt.DropShorterLongHelpFormatter("prog")
+
+        assert formatter._split_lines("first paragraph\n\nsecond paragraph", 80) == [
+            "first paragraph",
+            "",
+            "second paragraph",
+        ]
+        assert formatter._split_lines("one two three", 7) == ["one two", "three"]
+
     # testing would be more helpful with all help generated
     def test_drop_short_help1(self, parser: parseopt.Parser) -> None:
         group = parser.getgroup("general")