Improve auto_match for quotes

Only insert a pair of quotes if there are an even number of quotes
preceding the cursor. This way, if the cursor is inside an unclosed
string, typing the closing quote will not insert a pair.

IPython/terminal/shortcuts.py

@@ -139,12 +139,24 b' def create_ipython_shortcuts(shell):'
         event.current_buffer.insert_text("{}")
         event.current_buffer.cursor_left()
 
-    @kb.add('"', filter=focused_insert & auto_match & following_text(r"[,)}\]]|$"))
+    @kb.add(
+        '"',
+        filter=focused_insert
+        & auto_match
+        & preceding_text(r'^([^"]+|"[^"]*")*$')
+        & following_text(r"[,)}\]]|$"),
+    )
     def _(event):
         event.current_buffer.insert_text('""')
         event.current_buffer.cursor_left()
 
-    @kb.add("'", filter=focused_insert & auto_match & following_text(r"[,)}\]]|$"))
+    @kb.add(
+        "'",
+        filter=focused_insert
+        & auto_match
+        & preceding_text(r"^([^']+|'[^']*')*$")
+        & following_text(r"[,)}\]]|$"),
+    )
     def _(event):
         event.current_buffer.insert_text("''")
         event.current_buffer.cursor_left()
@@ -186,16 +198,6 b' def create_ipython_shortcuts(shell):'
         event.current_buffer.insert_text("{}" + dashes)
         event.current_buffer.cursor_left(len(dashes) + 1)
 
-    @kb.add('"', filter=focused_insert & auto_match & preceding_text(r".*(r|R)$"))
-    def _(event):
-        event.current_buffer.insert_text('""')
-        event.current_buffer.cursor_left()
-
-    @kb.add("'", filter=focused_insert & auto_match & preceding_text(r".*(r|R)$"))
-    def _(event):
-        event.current_buffer.insert_text("''")
-        event.current_buffer.cursor_left()
-
     # just move cursor
     @kb.add(")", filter=focused_insert & auto_match & following_text(r"^\)"))
     @kb.add("]", filter=focused_insert & auto_match & following_text(r"^\]"))