Fix contraction of '--' to '-' in Info format of Line Styles (bug #41585) * plot.txi: Can't use @qcode macro for '--' because it doesn't create a verbatim environment like @code. In this case, '--' is replaced by single en-dash in Info format. Instead, use explicit @ifinfo and @verb blocks to create '--' in Info format. * DASPK-opts.in: Add missing escaped quote (\") to documentation. * validateattributes.m: Remove extra ',' typo and end of @qcode instantiation.

--- a/doc/interpreter/plot.txi
+++ b/doc/interpreter/plot.txi
@@ -2643,7 +2643,13 @@
 @item @qcode{"-"}
 Solid line.  [default]
 
-@item @qcode{"--"}
+@c Special handling required to avoid '--' becoming single en-dash in Info
+@ifinfo
+@item @verb{"--"}
+@end ifinfo
+@iftex
+@item @code{"--"}
+@end iftex
 Dashed line.
 
 @item @qcode{":"}