Fixed: Correctly escapes backslashes in gnuplot strings

Fixes an issue where backslashes were not properly escaped when
generating strings for gnuplot, leading to incorrect rendering.

The gnuplot quoting function now escapes both backslashes and
single quotes to ensure correct string interpretation by gnuplot.

Refs: docs/benchmark

Author: acgetchell

scripts/criterion_dim_plot.py

@@ -43,6 +43,9 @@ class PlotRequest:
     log_y: bool
 
 
+Row = tuple[int, float, float, float, float, float, float, float, float, float]
+
+
 METRICS: Final[dict[str, Metric]] = {
     "det_via_lu": Metric(
         la_bench="la_stack_det_via_lu",
@@ -201,8 +204,8 @@ def _update_readme_table(readme_path: Path, marker_begin: str, marker_end: str,
 
 
 def _gp_quote(s: str) -> str:
-    # gnuplot supports single-quoted strings; escape single quotes.
-    return "'" + s.replace("'", "\\'") + "'"
+    # gnuplot supports single-quoted strings; escape backslashes and single quotes.
+    return "'" + s.replace("\\", "\\\\").replace("'", "\\'") + "'"
 
 
 def _render_svg_with_gnuplot(req: PlotRequest) -> None:
@@ -310,9 +313,6 @@ def _parse_args(argv: list[str]) -> argparse.Namespace:
     return parser.parse_args(argv)
 
 
-Row = tuple[int, float, float, float, float, float, float, float, float, float]
-
-
 def _resolve_under_root(root: Path, arg: str) -> Path:
     path = Path(arg)
     return path if path.is_absolute() else root / path

scripts/tests/test_criterion_dim_plot.py

@@ -42,6 +42,13 @@ def test_markdown_table_handles_zero_nalgebra_time() -> None:
     assert "| 2 | 10.000 | 0.000 | 100.000 | n/a | +90.0% |" in table
 
 
+def test_gp_quote_escapes_backslashes_and_quotes() -> None:
+    assert criterion_dim_plot._gp_quote("plain") == "'plain'"
+    assert criterion_dim_plot._gp_quote("a'b") == "'a\\'b'"
+    assert criterion_dim_plot._gp_quote("a\\b") == "'a\\\\b'"
+    assert criterion_dim_plot._gp_quote("a\\'b") == "'a\\\\\\'b'"
+
+
 def test_maybe_render_plot_handles_gnuplot_failure(capsys: pytest.CaptureFixture[str], monkeypatch: pytest.MonkeyPatch) -> None:
     # Simulate gnuplot existing but failing to run (CalledProcessError).
     def boom(_req: object) -> None: