Fixes for producing unicode tracebacks.

IPython/core/ultratb.py

@@ -102,6 +102,7 b' from IPython.utils import io'
 from IPython.utils import path as util_path
 from IPython.utils import py3compat
 from IPython.utils import pyfile
+from IPython.utils import ulinecache
 from IPython.utils.data import uniq_stable
 from IPython.utils.warn import info, error
 
@@ -230,7 +231,6 b' def fix_frame_records_filenames(records):'
 
 
 def _fixed_getinnerframes(etb, context=1,tb_offset=0):
-    import linecache
     LNUM_POS, LINES_POS, INDEX_POS =  2, 4, 5
 
     records  = fix_frame_records_filenames(inspect.getinnerframes(etb, context))
@@ -252,7 +252,7 b' def _fixed_getinnerframes(etb, context=1,tb_offset=0):'
         maybeStart = lnum-1 - context//2
         start =  max(maybeStart, 0)
         end   = start + context
-        lines = linecache.getlines(file)[start:end]
+        lines = ulinecache.getlines(file)[start:end]
         buf = list(records[i])
         buf[LNUM_POS] = lnum
         buf[INDEX_POS] = lnum - 1 - start
@@ -826,7 +826,7 b' class VerboseTB(TBTools):'
                 # Look up the corresponding source file.
                 file = pyfile.source_from_cache(file)
 
-            def linereader(file=file, lnum=[lnum], getline=linecache.getline):
+            def linereader(file=file, lnum=[lnum], getline=ulinecache.getline):
                 line = getline(file, lnum[0])
                 lnum[0] += 1
                 return line

IPython/utils/ulinecache.py

@@ -21,13 +21,18 b' else:'
     def getlines(filename, module_globals=None):
         """Get the lines (as unicode) for a file from the cache.
         Update the cache if it doesn't contain an entry for this file already."""
-        linesb = linecache.getlines(filename, module_globals=module_globals)
-        readline = openpy._list_readline(linesb)
+        lines = linecache.getlines(filename, module_globals=module_globals)
+        
+        # The bits we cache ourselves can be unicode.
+        if (not lines) or isinstance(lines[0], unicode):
+            return lines
+        
+        readline = openpy._list_readline(lines)
         try:
             encoding, _ = openpy.detect_encoding(readline)
         except SyntaxError:
             encoding = 'ascii'
-        return [l.decode(encoding, 'replace') for l in linesb]
+        return [l.decode(encoding, 'replace') for l in lines]
 
     # This is a straight copy of linecache.getline
     def getline(filename, lineno, module_globals=None):