fixes #2118 (#2120)

* Update CMakeLists.txt

* Fixes #2118:
vcs.Canvas.switchfonts() now works.
Added test to ensure it works correctly.

* Fixed error in test file.

* Added newline at end of test file.

Author: Edward Brown

Packages/vcs/vcs/Canvas.py

@@ -5548,7 +5548,9 @@ def switchfonts(self, font1, font2):
             raise vcsError(
                 "Error you must pass either a number or font name!, you passed for font 2: %s" %
                 font2)
-        return self.canvas.switchfontnumbers(*(index1, index2))
+        tmp = vcs.elements['fontNumber'][index1]
+        vcs.elements['fontNumber'][index1] = vcs.elements['fontNumber'][index2]
+        vcs.elements['fontNumber'][index2] = tmp
 
     def copyfontto(self, font1, font2):
         """

testing/vcs/CMakeLists.txt

@@ -433,6 +433,10 @@ cdat_add_test(test_vcs_export_text
   "${PYTHON_EXECUTABLE}"
   ${cdat_SOURCE_DIR}/testing/vcs/test_vcs_export_text.py
   )
+cdat_add_test(test_vcs_canvas_switchfonts
+  "${PYTHON_EXECUTABLE}"
+  ${cdat_SOURCE_DIR}/testing/vcs/test_vcs_canvas_switchfonts.py
+  )
 ##############################################################################
 #
 # These tests perform plotting and need sample data

testing/vcs/test_vcs_canvas_switchfonts.py

@@ -0,0 +1,19 @@
+import vcs
+
+a=vcs.init()
+font1 = a.getfont(1)
+font2 = a.getfont(2)
+
+# switchfont() by number
+a.switchfonts(1,2)
+new_font1 = a.getfont(1)
+new_font2 = a.getfont(2)
+assert(font1 == new_font2)
+assert(font2 == new_font1)
+
+# switchfont() by name
+a.switchfonts(font1,font2)
+new_font1 = a.getfont(1)
+new_font2 = a.getfont(2)
+assert(font1 == new_font1)
+assert(font2 == new_font2)