Sage Ticket #10717: Prime typeset badly on plots

Supported by Sage Days 29
139d96937a67d31f30e9e52863f792a13a77cf1c
commit 139d96937a67d31f30e9e52863f792a13a77cf1c
diff --git a/lib/matplotlib/_mathtext_data.py b/lib/matplotlib/_mathtext_data.py
@@ -160,8 +160,6 @@
     r'\nwarrow'                  : ('cmsy10',  65),
     r'\swarrow'                  : ('cmsy10', 116),
     r'\propto'                   : ('cmsy10',  15),
-    r'\prime'                    : ('cmsy10',  73),
-    r"'"                         : ('cmsy10',  73),
     r'\infty'                    : ('cmsy10',  32),
     r'\in'                       : ('cmsy10',  59),
     r'\ni'                       : ('cmsy10', 122),

diff --git a/lib/matplotlib/mathtext.py b/lib/matplotlib/mathtext.py
@@ -2456,6 +2456,8 @@ def customspace(self, s, loc, toks):
     def symbol(self, s, loc, toks):
         # print "symbol", toks
         c = toks[0]
+        if c == "'":
+            c = '\prime'
         try:
             char = Char(c, self.get_state())
         except ValueError: