Inputsplitter flushes transformers before retrieving source.

IPython/core/inputsplitter.py

@@ -524,14 +524,30 b' class IPythonInputSplitter(InputSplitter):'
         self._buffer_raw[:] = []
         self.source_raw = ''
         self.transformer_accumulating = False
+        for t in self.transforms:
+            t.reset()
+    
+    def flush_transformers(self):
+        out = None
+        for t in self.transforms:
+            tmp = t.reset()
+            if tmp:
+                out = tmp
+        if out:
+            self._store(out)
 
     def source_raw_reset(self):
         """Return input and raw source and perform a full reset.
         """
+        self.flush_transformers()
         out = self.source
         out_r = self.source_raw
         self.reset()
         return out, out_r
+    
+    def source_reset(self):
+        self.flush_transformers()
+        return super(IPythonInputSplitter, self).source_reset()
 
     def push_accepts_more(self):
         if self.transformer_accumulating:

IPython/core/inputtransformer.py

@@ -66,7 +66,7 b' class CoroutineInputTransformer(InputTransformer):'
         return self.coro.send(line)
     
     def reset(self):
-        self.coro.send(None)
+        return self.coro.send(None)
 
 
 # Utilities