Let pgf backend use bracket delimiters for detecting math mode (rebased).

Callum Watson · Callum Watson · commit 2588b1d492f6 · 2022-07-04T18:38:33.000+01:00
diff --git a/lib/matplotlib/backends/backend_pgf.py b/lib/matplotlib/backends/backend_pgf.py
@@ -82,7 +82,7 @@ def _get_preamble():
 
 
 _NO_ESCAPE = r"(?<!\\)(?:\\\\)*"
-_split_math = re.compile(_NO_ESCAPE + r"\$").split
+_split_math = re.compile(_NO_ESCAPE + r"(?:\$|\\[()])").split
 _replace_escapetext = functools.partial(
     # When the next character is _, ^, $, or % (not preceded by an escape),
     # insert a backslash.
