Don't crash qt figure options on unknown marker styles.

anntzer · anntzer · commit 0dc4e4350355 · 2018-05-09T01:28:34.000-07:00
Currently, if a plot uses a "custom" marker style (e.g., a mathtext
string, `plt.plot([1, 2], ls="none", marker="$1/2$")`, or a n-gon,
`marker=(7, 0)`), trying to open the qt figure options editor will crash
the process because of an unhandled KeyError in `prepare_data` (at
`canonical_init = name2short[d[init]]`).

Instead, create an entry on-the-fly for that custom style.
diff --git a/lib/matplotlib/backends/qt_editor/figureoptions.py b/lib/matplotlib/backends/qt_editor/figureoptions.py
@@ -93,6 +93,8 @@ def prepare_data(d, init):
         FormLayout combobox, namely `[initial_name, (shorthand,
         style_name), (shorthand, style_name), ...]`.
         """
+        if init not in d:
+            d = {**d, init: str(init)}
         # Drop duplicate shorthands from dict (by overwriting them during
         # the dict comprehension).
         name2short = {name: short for short, name in d.items()}
