updated for version 7.3.1230v7.3.1230

Problem:    Python: Exception messages are not clear.
Solution:   Make exception messages more verbose. (ZyX)

6 files changed, 347 insertions, 295 deletions

diff --git a/src/if_py_both.h b/src/if_py_both.h
index 46625049d8..e11c62e866 100644
--- a/src/if_py_both.h
+++ b/src/if_py_both.h
@@ -29,9 +29,25 @@ static const char *vim_special_path = "_vim_path_";
 #define PyErr_SET_STRING(exc, str) PyErr_SetString(exc, _(str))
 #define PyErr_SetVim(str) PyErr_SetString(VimError, str)
 #define PyErr_SET_VIM(str) PyErr_SET_STRING(VimError, str)
+#define PyErr_FORMAT(exc, str, tail) PyErr_Format(exc, _(str), tail)
+#define PyErr_VIM_FORMAT(str, tail) PyErr_FORMAT(VimError, str, tail)
+
+#define Py_TYPE_NAME(obj) (obj->ob_type->tp_name == NULL \
+	? "(NULL)" \
+	: obj->ob_type->tp_name)
 
 #define RAISE_NO_EMPTY_KEYS PyErr_SET_STRING(PyExc_ValueError, \
 						"empty keys are not allowed")
+#define RAISE_LOCKED(type) PyErr_SET_VIM(_(type " is locked"))
+#define RAISE_LOCKED_DICTIONARY RAISE_LOCKED("dictionary")
+#define RAISE_LOCKED_LIST RAISE_LOCKED("list")
+#define RAISE_UNDO_FAIL PyErr_SET_VIM("cannot save undo information")
+#define RAISE_LINE_FAIL(act) PyErr_SET_VIM("cannot " act " line")
+#define RAISE_KEY_ADD_FAIL(key) \
+    PyErr_VIM_FORMAT("failed to add key '%s' to dictionary", key)
+#define RAISE_INVALID_INDEX_TYPE(idx) \
+    PyErr_FORMAT(PyExc_TypeError, "index must be int or slice, not %s", \
+	    Py_TYPE_NAME(idx));
 
 #define INVALID_BUFFER_VALUE ((buf_T *)(-1))
 #define INVALID_WINDOW_VALUE ((win_T *)(-1))
@@ -122,7 +138,13 @@ StringToChars(PyObject *object, PyObject **todecref)
     }
     else
     {
-	PyErr_SET_STRING(PyExc_TypeError, "object must be string");
+	PyErr_FORMAT(PyExc_TypeError,
+#if PY_MAJOR_VERSION < 3
+		"expected str() or unicode() instance, but got %s"
+#else
+		"expected bytes() or str() instance, but got %s"
+#endif
+		, Py_TYPE_NAME(object));
 	return NULL;
     }
 
@@ -231,7 +253,7 @@ OutputSetattr(OutputObject *self, char *name, PyObject *val)
 	return 0;
     }
 
-    PyErr_SET_STRING(PyExc_AttributeError, "invalid attribute");
+    PyErr_FORMAT(PyExc_AttributeError, "invalid attribute: %s", name);
     return -1;
 }
 
@@ -967,11 +989,19 @@ call_load_module(char *name, int len, PyObject *find_module_result)
 {
     PyObject	*fd, *pathname, *description;
 
-    if (!PyTuple_Check(find_module_result)
-	    || PyTuple_GET_SIZE(find_module_result) != 3)
+    if (!PyTuple_Check(find_module_result))
     {
-	PyErr_SET_STRING(PyExc_TypeError,
-		"expected 3-tuple as imp.find_module() result");
+	PyErr_FORMAT(PyExc_TypeError,
+		"expected 3-tuple as imp.find_module() result, but got %s",
+		Py_TYPE_NAME(find_module_result));
+	return NULL;
+    }
+    if (PyTuple_GET_SIZE(find_module_result) != 3)
+    {
+	PyErr_FORMAT(PyExc_TypeError,
+		"expected 3-tuple as imp.find_module() result, but got "
+		"tuple of size %d",
+		(int) PyTuple_GET_SIZE(find_module_result));
 	return NULL;
     }
 
@@ -1377,7 +1407,7 @@ DictionarySetattr(DictionaryObject *self, char *name, PyObject *val)
     }
     else
     {
-	PyErr_SET_STRING(PyExc_AttributeError, "cannot set this attribute");
+	PyErr_FORMAT(PyExc_AttributeError, "cannot set attribute %s", name);
 	return -1;
     }
 }
@@ -1459,7 +1489,7 @@ _DictionaryItem(DictionaryObject *self, PyObject *args, int flags)
     {
 	if (dict->dv_lock)
 	{
-	    PyErr_SET_VIM("dict is locked");
+	    RAISE_LOCKED_DICTIONARY;
 	    Py_DECREF(r);
 	    return NULL;
 	}
@@ -1562,7 +1592,7 @@ DictionaryAssItem(
 
     if (dict->dv_lock)
     {
-	PyErr_SET_VIM("dict is locked");
+	RAISE_LOCKED_DICTIONARY;
 	return -1;
     }
 
@@ -1614,10 +1644,10 @@ DictionaryAssItem(
 
 	if (dict_add(dict, di) == FAIL)
 	{
-	    Py_XDECREF(todecref);
 	    vim_free(di);
 	    dictitem_free(di);
-	    PyErr_SET_VIM("failed to add key to dictionary");
+	    RAISE_KEY_ADD_FAIL(key);
+	    Py_XDECREF(todecref);
 	    return -1;
 	}
     }
@@ -1725,7 +1755,7 @@ DictionaryUpdate(DictionaryObject *self, PyObject *args, PyObject *kwargs)
 
     if (dict->dv_lock)
     {
-	PyErr_SET_VIM("dict is locked");
+	RAISE_LOCKED_DICTIONARY;
 	return NULL;
     }
 
@@ -1781,8 +1811,10 @@ DictionaryUpdate(DictionaryObject *self, PyObject *args, PyObject *kwargs)
 		{
 		    Py_DECREF(iterator);
 		    Py_DECREF(fast);
-		    PyErr_SET_STRING(PyExc_ValueError,
-			    "expected sequence element of size 2");
+		    PyErr_FORMAT(PyExc_ValueError,
+			    "expected sequence element of size 2, "
+			    "but got sequence of size %d",
+			    PySequence_Fast_GET_SIZE(fast));
 		    return NULL;
 		}
 
@@ -1823,9 +1855,9 @@ DictionaryUpdate(DictionaryObject *self, PyObject *args, PyObject *kwargs)
 
 		if (dict_add(dict, di) == FAIL)
 		{
+		    RAISE_KEY_ADD_FAIL(di->di_key);
 		    Py_DECREF(iterator);
 		    dictitem_free(di);
-		    PyErr_SET_VIM("failed to add key to dictionary");
 		    return NULL;
 		}
 	    }
@@ -2085,7 +2117,9 @@ ListItem(ListObject *self, Py_ssize_t index)
     li = list_find(self->list, (long) index);
     if (li == NULL)
     {
-	PyErr_SET_VIM("internal error: failed to get vim list item");
+	/* No more suitable format specifications in python-2.3 */
+	PyErr_VIM_FORMAT("internal error: failed to get vim list item %d",
+		(int) index);
 	return NULL;
     }
     return ConvertToPyObject(&li->li_tv);
@@ -2198,7 +2232,7 @@ ListAssItem(ListObject *self, Py_ssize_t index, PyObject *obj)
 
     if (l->lv_lock)
     {
-	PyErr_SET_VIM("list is locked");
+	RAISE_LOCKED_LIST;
 	return -1;
     }
     if (index>length || (index==length && obj==NULL))
@@ -2252,7 +2286,7 @@ ListAssSlice(ListObject *self, Py_ssize_t first, Py_ssize_t last, PyObject *obj)
 
     if (l->lv_lock)
     {
-	PyErr_SET_VIM("list is locked");
+	RAISE_LOCKED_LIST;
 	return -1;
     }
 
@@ -2265,7 +2299,7 @@ ListAssSlice(ListObject *self, Py_ssize_t first, Py_ssize_t last, PyObject *obj)
 	li = list_find(l, (long) first);
 	if (li == NULL)
 	{
-	    PyErr_SET_VIM("internal error: no vim list item");
+	    PyErr_VIM_FORMAT("internal error: no vim list item %d", (int)first);
 	    return -1;
 	}
 	if (last > first)
@@ -2315,7 +2349,7 @@ ListConcatInPlace(ListObject *self, PyObject *obj)
 
     if (l->lv_lock)
     {
-	PyErr_SET_VIM("list is locked");
+	RAISE_LOCKED_LIST;
 	return NULL;
     }
 
@@ -2375,7 +2409,7 @@ ListSetattr(ListObject *self, char *name, PyObject *val)
     }
     else
     {
-	PyErr_SET_STRING(PyExc_AttributeError, "cannot set this attribute");
+	PyErr_FORMAT(PyExc_AttributeError, "cannot set attribute %s", name);
 	return -1;
     }
 }
@@ -2410,8 +2444,8 @@ FunctionNew(PyTypeObject *subtype, char_u *name)
     {
 	if (!translated_function_exists(name))
 	{
-	    PyErr_SET_STRING(PyExc_ValueError,
-		    "unnamed function does not exist");
+	    PyErr_FORMAT(PyExc_ValueError,
+		    "unnamed function %s does not exist", name);
 	    return NULL;
 	}
 	self->name = vim_strsave(name);
@@ -2422,7 +2456,7 @@ FunctionNew(PyTypeObject *subtype, char_u *name)
 				    vim_strchr(name, AUTOLOAD_CHAR) == NULL))
 		== NULL)
 	{
-	    PyErr_SET_STRING(PyExc_ValueError, "function does not exist");
+	    PyErr_FORMAT(PyExc_ValueError, "function %s does not exist", name);
 	    return NULL;
 	}
 
@@ -2515,7 +2549,7 @@ FunctionCall(FunctionObject *self, PyObject *argsObject, PyObject *kwargs)
     else if (error != OK)
     {
 	result = NULL;
-	PyErr_SET_VIM("failed to run function");
+	PyErr_VIM_FORMAT("failed to run function %s", (char *)name);
     }
     else
 	result = ConvertToPyObject(&rettv);
@@ -2770,14 +2804,16 @@ OptionsAssItem(OptionsObject *self, PyObject *keyObject, PyObject *valObject)
     {
 	if (self->opt_type == SREQ_GLOBAL)
 	{
-	    PyErr_SET_STRING(PyExc_ValueError, "unable to unset global option");
+	    PyErr_FORMAT(PyExc_ValueError,
+		    "unable to unset global option %s", key);
 	    Py_XDECREF(todecref);
 	    return -1;
 	}
 	else if (!(flags & SOPT_GLOBAL))
 	{
-	    PyErr_SET_STRING(PyExc_ValueError, "unable to unset option "
-					       "without global value");
+	    PyErr_FORMAT(PyExc_ValueError,
+		    "unable to unset option %s "
+		    "which does not have global value", key);
 	    Py_XDECREF(todecref);
 	    return -1;
 	}
@@ -3195,7 +3231,7 @@ WindowSetattr(WindowObject *self, char *name, PyObject *val)
 
     if (strcmp(name, "buffer") == 0)
     {
-	PyErr_SET_STRING(PyExc_TypeError, "readonly attribute");
+	PyErr_SET_STRING(PyExc_TypeError, "readonly attribute: buffer");
 	return -1;
     }
     else if (strcmp(name, "cursor") == 0)
@@ -3558,9 +3594,9 @@ SetBufferLine(buf_T *buf, PyInt n, PyObject *line, PyInt *len_change)
 	VimTryStart();
 
 	if (u_savedel((linenr_T)n, 1L) == FAIL)
-	    PyErr_SET_VIM("cannot save undo information");
+	    RAISE_UNDO_FAIL;
 	else if (ml_delete((linenr_T)n, FALSE) == FAIL)
-	    PyErr_SET_VIM("cannot delete line");
+	    RAISE_LINE_FAIL("delete");
 	else
 	{
 	    if (buf == savebuf)
@@ -3594,12 +3630,12 @@ SetBufferLine(buf_T *buf, PyInt n, PyObject *line, PyInt *len_change)
 
 	if (u_savesub((linenr_T)n) == FAIL)
 	{
-	    PyErr_SET_VIM("cannot save undo information");
+	    RAISE_UNDO_FAIL;
 	    vim_free(save);
 	}
 	else if (ml_replace((linenr_T)n, (char_u *)save, FALSE) == FAIL)
 	{
-	    PyErr_SET_VIM("cannot replace line");
+	    RAISE_LINE_FAIL("replace");
 	    vim_free(save);
 	}
 	else
@@ -3654,14 +3690,14 @@ SetBufferLineList(buf_T *buf, PyInt lo, PyInt hi, PyObject *list, PyInt *len_cha
 	switch_buffer(&savebuf, buf);
 
 	if (u_savedel((linenr_T)lo, (long)n) == FAIL)
-	    PyErr_SET_VIM("cannot save undo information");
+	    RAISE_UNDO_FAIL;
 	else
 	{
 	    for (i = 0; i < n; ++i)
 	    {
 		if (ml_delete((linenr_T)lo, FALSE) == FAIL)
 		{
-		    PyErr_SET_VIM("cannot delete line");
+		    RAISE_LINE_FAIL("delete");
 		    break;
 		}
 	    }
@@ -3722,7 +3758,7 @@ SetBufferLineList(buf_T *buf, PyInt lo, PyInt hi, PyObject *list, PyInt *len_cha
 	switch_buffer(&savebuf, buf);
 
 	if (u_save((linenr_T)(lo-1), (linenr_T)hi) == FAIL)
-	    PyErr_SET_VIM("cannot save undo information");
+	    RAISE_UNDO_FAIL;
 
 	/* If the size of the range is reducing (ie, new_len < old_len) we
 	 * need to delete some old_len. We do this at the start, by
@@ -3733,7 +3769,7 @@ SetBufferLineList(buf_T *buf, PyInt lo, PyInt hi, PyObject *list, PyInt *len_cha
 	    for (i = 0; i < old_len - new_len; ++i)
 		if (ml_delete((linenr_T)lo, FALSE) == FAIL)
 		{
-		    PyErr_SET_VIM("cannot delete line");
+		    RAISE_LINE_FAIL("delete");
 		    break;
 		}
 	    extra -= i;
@@ -3749,7 +3785,7 @@ SetBufferLineList(buf_T *buf, PyInt lo, PyInt hi, PyObject *list, PyInt *len_cha
 		if (ml_replace((linenr_T)(lo+i), (char_u *)array[i], FALSE)
 								      == FAIL)
 		{
-		    PyErr_SET_VIM("cannot replace line");
+		    RAISE_LINE_FAIL("replace");
 		    break;
 		}
 	}
@@ -3767,7 +3803,7 @@ SetBufferLineList(buf_T *buf, PyInt lo, PyInt hi, PyObject *list, PyInt *len_cha
 		if (ml_append((linenr_T)(lo + i - 1),
 					(char_u *)array[i], 0, FALSE) == FAIL)
 		{
-		    PyErr_SET_VIM("cannot insert line");
+		    RAISE_LINE_FAIL("insert");
 		    break;
 		}
 		vim_free(array[i]);
@@ -3844,9 +3880,9 @@ InsertBufferLines(buf_T *buf, PyInt n, PyObject *lines, PyInt *len_change)
 	switch_buffer(&savebuf, buf);
 
 	if (u_save((linenr_T)n, (linenr_T)(n+1)) == FAIL)
-	    PyErr_SET_VIM("cannot save undo information");
+	    RAISE_UNDO_FAIL;
 	else if (ml_append((linenr_T)n, (char_u *)str, 0, FALSE) == FAIL)
-	    PyErr_SET_VIM("cannot insert line");
+	    RAISE_LINE_FAIL("insert");
 	else
 	    appended_lines_mark((linenr_T)n, 1L);
 
@@ -3895,7 +3931,7 @@ InsertBufferLines(buf_T *buf, PyInt n, PyObject *lines, PyInt *len_change)
 	switch_buffer(&savebuf, buf);
 
 	if (u_save((linenr_T)n, (linenr_T)(n + 1)) == FAIL)
-	    PyErr_SET_VIM("cannot save undo information");
+	    RAISE_UNDO_FAIL;
 	else
 	{
 	    for (i = 0; i < size; ++i)
@@ -3903,7 +3939,7 @@ InsertBufferLines(buf_T *buf, PyInt n, PyObject *lines, PyInt *len_change)
 		if (ml_append((linenr_T)(n + i),
 					(char_u *)array[i], 0, FALSE) == FAIL)
 		{
-		    PyErr_SET_VIM("cannot insert line");
+		    RAISE_LINE_FAIL("insert");
 
 		    /* Free the rest of the lines */
 		    while (i < size)
@@ -4668,7 +4704,9 @@ CurrentSetattr(PyObject *self UNUSED, char *name, PyObject *value)
 
 	if (value->ob_type != &BufferType)
 	{
-	    PyErr_SET_STRING(PyExc_TypeError, "expected vim.Buffer object");
+	    PyErr_FORMAT(PyExc_TypeError,
+		    "expected vim.Buffer object, but got %s",
+		    Py_TYPE_NAME(value));
 	    return -1;
 	}
 
@@ -4681,7 +4719,7 @@ CurrentSetattr(PyObject *self UNUSED, char *name, PyObject *value)
 	{
 	    if (VimTryEnd())
 		return -1;
-	    PyErr_SET_VIM("failed to switch to given buffer");
+	    PyErr_VIM_FORMAT("failed to switch to buffer %d", count);
 	    return -1;
 	}
 
@@ -4693,7 +4731,9 @@ CurrentSetattr(PyObject *self UNUSED, char *name, PyObject *value)
 
 	if (value->ob_type != &WindowType)
 	{
-	    PyErr_SET_STRING(PyExc_TypeError, "expected vim.Window object");
+	    PyErr_FORMAT(PyExc_TypeError,
+		    "expected vim.Window object, but got %s",
+		    Py_TYPE_NAME(value));
 	    return -1;
 	}
 
@@ -4725,7 +4765,9 @@ CurrentSetattr(PyObject *self UNUSED, char *name, PyObject *value)
     {
 	if (value->ob_type != &TabPageType)
 	{
-	    PyErr_SET_STRING(PyExc_TypeError, "expected vim.TabPage object");
+	    PyErr_FORMAT(PyExc_TypeError,
+		    "expected vim.TabPage object, but got %s",
+		    Py_TYPE_NAME(value));
 	    return -1;
 	}
 
@@ -5003,10 +5045,10 @@ pydict_to_tv(PyObject *obj, typval_T *tv, PyObject *lookup_dict)
 
 	if (dict_add(dict, di) == FAIL)
 	{
+	    RAISE_KEY_ADD_FAIL(di->di_key);
 	    clear_tv(&di->di_tv);
 	    vim_free(di);
 	    dict_unref(dict);
-	    PyErr_SET_VIM("failed to add key to dictionary");
 	    return -1;
 	}
     }
@@ -5105,10 +5147,10 @@ pymap_to_tv(PyObject *obj, typval_T *tv, PyObject *lookup_dict)
 
 	if (dict_add(dict, di) == FAIL)
 	{
+	    RAISE_KEY_ADD_FAIL(di->di_key);
 	    Py_DECREF(iterator);
 	    dictitem_free(di);
 	    dict_unref(dict);
-	    PyErr_SET_VIM("failed to add key to dictionary");
 	    return -1;
 	}
     }
@@ -5216,8 +5258,9 @@ ConvertFromPyMapping(PyObject *obj, typval_T *tv)
 	r = convert_dl(obj, tv, pymap_to_tv, lookup_dict);
     else
     {
-	PyErr_SET_STRING(PyExc_TypeError,
-		"unable to convert object to vim dictionary");
+	PyErr_FORMAT(PyExc_TypeError,
+		"unable to convert %s to vim dictionary",
+		Py_TYPE_NAME(obj));
 	r = -1;
     }
     Py_DECREF(lookup_dict);
@@ -5326,8 +5369,9 @@ _ConvertFromPyObject(PyObject *obj, typval_T *tv, PyObject *lookup_dict)
 	return convert_dl(obj, tv, pymap_to_tv, lookup_dict);
     else
     {
-	PyErr_SET_STRING(PyExc_TypeError,
-		"unable to convert to vim structure");
+	PyErr_FORMAT(PyExc_TypeError,
+		"unable to convert %s to vim structure",
+		Py_TYPE_NAME(obj));
 	return -1;
     }
     return 0;
@@ -5338,7 +5382,7 @@ ConvertToPyObject(typval_T *tv)
 {
     if (tv == NULL)
     {
-	PyErr_SET_VIM("NULL reference passed");
+	PyErr_SET_VIM("internal error: NULL reference passed");
 	return NULL;
     }
     switch (tv->v_type)
diff --git a/src/if_python.c b/src/if_python.c
index ed51119912..28cd36f853 100644
--- a/src/if_python.c
+++ b/src/if_python.c
@@ -160,6 +160,7 @@ struct PyMethodDef { Py_ssize_t a; };
 # define PyErr_BadArgument dll_PyErr_BadArgument
 # define PyErr_NewException dll_PyErr_NewException
 # define PyErr_Clear dll_PyErr_Clear
+# define PyErr_Format dll_PyErr_Format
 # define PyErr_PrintEx dll_PyErr_PrintEx
 # define PyErr_NoMemory dll_PyErr_NoMemory
 # define PyErr_Occurred dll_PyErr_Occurred
@@ -301,6 +302,7 @@ static int(*dll_PyDict_SetItemString)(PyObject *dp, char *key, PyObject *item);
 static int(*dll_PyErr_BadArgument)(void);
 static PyObject *(*dll_PyErr_NewException)(char *, PyObject *, PyObject *);
 static void(*dll_PyErr_Clear)(void);
+static PyObject*(*dll_PyErr_Format)(PyObject *, const char *, ...);
 static void(*dll_PyErr_PrintEx)(int);
 static PyObject*(*dll_PyErr_NoMemory)(void);
 static PyObject*(*dll_PyErr_Occurred)(void);
@@ -473,6 +475,7 @@ static struct
     {"PyErr_BadArgument", (PYTHON_PROC*)&dll_PyErr_BadArgument},
     {"PyErr_NewException", (PYTHON_PROC*)&dll_PyErr_NewException},
     {"PyErr_Clear", (PYTHON_PROC*)&dll_PyErr_Clear},
+    {"PyErr_Format", (PYTHON_PROC*)&dll_PyErr_Format},
     {"PyErr_PrintEx", (PYTHON_PROC*)&dll_PyErr_PrintEx},
     {"PyErr_NoMemory", (PYTHON_PROC*)&dll_PyErr_NoMemory},
     {"PyErr_Occurred", (PYTHON_PROC*)&dll_PyErr_Occurred},
diff --git a/src/if_python3.c b/src/if_python3.c
index 7155bc1c61..9bb2a4f7f5 100644
--- a/src/if_python3.c
+++ b/src/if_python3.c
@@ -122,6 +122,7 @@
 # define PyDict_SetItemString py3_PyDict_SetItemString
 # define PyErr_BadArgument py3_PyErr_BadArgument
 # define PyErr_Clear py3_PyErr_Clear
+# define PyErr_Format py3_PyErr_Format
 # define PyErr_PrintEx py3_PyErr_PrintEx
 # define PyErr_NoMemory py3_PyErr_NoMemory
 # define PyErr_Occurred py3_PyErr_Occurred
@@ -337,6 +338,7 @@ static int (*py3_PyMem_Free)(void *);
 static void* (*py3_PyMem_Malloc)(size_t);
 static int (*py3_Py_IsInitialized)(void);
 static void (*py3_PyErr_Clear)(void);
+static PyObject* (*py3_PyErr_Format)(PyObject *, const char *, ...);
 static void (*py3_PyErr_PrintEx)(int);
 static PyObject*(*py3__PyObject_Init)(PyObject *, PyTypeObject *);
 static iternextfunc py3__PyObject_NextNotImplemented;
@@ -485,6 +487,7 @@ static struct
     {"_Py_FalseStruct", (PYTHON_PROC*)&py3__Py_FalseStruct},
     {"_Py_TrueStruct", (PYTHON_PROC*)&py3__Py_TrueStruct},
     {"PyErr_Clear", (PYTHON_PROC*)&py3_PyErr_Clear},
+    {"PyErr_Format", (PYTHON_PROC*)&py3_PyErr_Format},
     {"PyErr_PrintEx", (PYTHON_PROC*)&py3_PyErr_PrintEx},
     {"PyObject_Init", (PYTHON_PROC*)&py3__PyObject_Init},
     {"PyModule_AddObject", (PYTHON_PROC*)&py3_PyModule_AddObject},
@@ -1169,7 +1172,7 @@ BufferSubscript(PyObject *self, PyObject* idx)
     }
     else
     {
-	PyErr_SET_STRING(PyExc_TypeError, "index must be int or slice");
+	RAISE_INVALID_INDEX_TYPE(idx);
 	return NULL;
     }
 }
@@ -1203,7 +1206,7 @@ BufferAsSubscript(PyObject *self, PyObject* idx, PyObject* val)
     }
     else
     {
-	PyErr_SET_STRING(PyExc_TypeError, "index must be int or slice");
+	RAISE_INVALID_INDEX_TYPE(idx);
 	return -1;
     }
 }
@@ -1285,7 +1288,7 @@ RangeSubscript(PyObject *self, PyObject* idx)
     }
     else
     {
-	PyErr_SET_STRING(PyExc_TypeError, "index must be int or slice");
+	RAISE_INVALID_INDEX_TYPE(idx);
 	return NULL;
     }
 }
@@ -1312,7 +1315,7 @@ RangeAsSubscript(PyObject *self, PyObject *idx, PyObject *val)
     }
     else
     {
-	PyErr_SET_STRING(PyExc_TypeError, "index must be int or slice");
+	RAISE_INVALID_INDEX_TYPE(idx);
 	return -1;
     }
 }
@@ -1491,7 +1494,7 @@ ListSubscript(PyObject *self, PyObject* idx)
     }
     else
     {
-	PyErr_SET_STRING(PyExc_TypeError, "index must be int or slice");
+	RAISE_INVALID_INDEX_TYPE(idx);
 	return NULL;
     }
 }
@@ -1515,7 +1518,7 @@ ListAsSubscript(PyObject *self, PyObject *idx, PyObject *obj)
     }
     else
     {
-	PyErr_SET_STRING(PyExc_TypeError, "index must be int or slice");
+	RAISE_INVALID_INDEX_TYPE(idx);
 	return -1;
     }
 }
diff --git a/src/testdir/test86.ok b/src/testdir/test86.ok
index 27a1372333..d94e0eaf77 100644
--- a/src/testdir/test86.ok
+++ b/src/testdir/test86.ok
@@ -439,106 +439,106 @@ test86.in
 >> OutputSetattr
 del sys.stdout.softspace:AttributeError:("can't delete OutputObject attributes",)
 sys.stdout.softspace = []:TypeError:('softspace must be an integer',)
-sys.stdout.attr = None:AttributeError:('invalid attribute',)
+sys.stdout.attr = None:AttributeError:('invalid attribute: attr',)
 >> OutputWrite
 sys.stdout.write(None):TypeError:('coercing to Unicode: need string or buffer, NoneType found',)
 >> OutputWriteLines
 sys.stdout.writelines(None):TypeError:("'NoneType' object is not iterable",)
 sys.stdout.writelines([1]):TypeError:('coercing to Unicode: need string or buffer, int found',)
 > VimCommand
-vim.command(1):TypeError:('object must be string',)
+vim.command(1):TypeError:('expected str() or unicode() instance, but got int',)
 > VimToPython
 > VimEval
-vim.eval(1):TypeError:('object must be string',)
+vim.eval(1):TypeError:('expected str() or unicode() instance, but got int',)
 > VimEvalPy
-vim.bindeval(1):TypeError:('object must be string',)
+vim.bindeval(1):TypeError:('expected str() or unicode() instance, but got int',)
 > VimStrwidth
-vim.strwidth(1):TypeError:('object must be string',)
+vim.strwidth(1):TypeError:('expected str() or unicode() instance, but got int',)
 > Dictionary
 >> DictionaryConstructor
-vim.Dictionary("abc"):ValueError:('expected sequence element of size 2',)
+vim.Dictionary("abc"):ValueError:('expected sequence element of size 2, but got sequence of size 1',)
 >> DictionarySetattr
 del d.locked:AttributeError:('cannot delete vim.Dictionary attributes',)
 d.locked = FailingTrue():NotImplementedError:()
 vim.vvars.locked = False:TypeError:('cannot modify fixed dictionary',)
-d.scope = True:AttributeError:('cannot set this attribute',)
-d.xxx = True:AttributeError:('cannot set this attribute',)
+d.scope = True:AttributeError:('cannot set attribute scope',)
+d.xxx = True:AttributeError:('cannot set attribute xxx',)
 >> _DictionaryItem
 d.get("a", 2, 3):TypeError:('function takes at most 2 arguments (3 given)',)
 >>> Testing StringToChars using d.get(%s)
-d.get(1):TypeError:('object must be string',)
+d.get(1):TypeError:('expected str() or unicode() instance, but got int',)
 d.get(u"\0"):TypeError:('expected string without null bytes',)
 d.get("\0"):TypeError:('expected string without null bytes',)
 <<< Finished
 d.pop("a"):KeyError:('a',)
-dl.pop("a"):error:('dict is locked',)
+dl.pop("a"):error:('dictionary is locked',)
 >> DictionaryIterNext
 for i in ned: ned["a"] = 1:RuntimeError:('hashtab changed during iteration',)
 >> DictionaryAssItem
-dl["b"] = 1:error:('dict is locked',)
+dl["b"] = 1:error:('dictionary is locked',)
 >>> Testing StringToChars using d[%s] = 1
-d[1] = 1:TypeError:('object must be string',)
+d[1] = 1:TypeError:('expected str() or unicode() instance, but got int',)
 d[u"\0"] = 1:TypeError:('expected string without null bytes',)
 d["\0"] = 1:TypeError:('expected string without null bytes',)
 <<< Finished
 >>> Testing StringToChars using d["a"] = {%s : 1}
-d["a"] = {1 : 1}:TypeError:('object must be string',)
+d["a"] = {1 : 1}:TypeError:('expected str() or unicode() instance, but got int',)
 d["a"] = {u"\0" : 1}:TypeError:('expected string without null bytes',)
 d["a"] = {"\0" : 1}:TypeError:('expected string without null bytes',)
 <<< Finished
 >>> Testing StringToChars using d["a"] = {"abc" : {%s : 1}}
-d["a"] = {"abc" : {1 : 1}}:TypeError:('object must be string',)
+d["a"] = {"abc" : {1 : 1}}:TypeError:('expected str() or unicode() instance, but got int',)
 d["a"] = {"abc" : {u"\0" : 1}}:TypeError:('expected string without null bytes',)
 d["a"] = {"abc" : {"\0" : 1}}:TypeError:('expected string without null bytes',)
 <<< Finished
 >>> Testing StringToChars using d["a"] = {"abc" : Mapping({%s : 1})}
-d["a"] = {"abc" : Mapping({1 : 1})}:TypeError:('object must be string',)
+d["a"] = {"abc" : Mapping({1 : 1})}:TypeError:('expected str() or unicode() instance, but got int',)
 d["a"] = {"abc" : Mapping({u"\0" : 1})}:TypeError:('expected string without null bytes',)
 d["a"] = {"abc" : Mapping({"\0" : 1})}:TypeError:('expected string without null bytes',)
 <<< Finished
 >>> Testing *Iter* using d["a"] = {"abc" : %s}
-d["a"] = {"abc" : FailingIter()}:TypeError:('unable to convert to vim structure',)
+d["a"] = {"abc" : FailingIter()}:TypeError:('unable to convert FailingIter to vim structure',)
 d["a"] = {"abc" : FailingIterNext()}:NotImplementedError:()
 <<< Finished
 >>> Testing ConvertFromPyObject using d["a"] = {"abc" : %s}
-d["a"] = {"abc" : None}:TypeError:('unable to convert to vim structure',)
+d["a"] = {"abc" : None}:TypeError:('unable to convert NoneType to vim structure',)
 d["a"] = {"abc" : {"": 1}}:ValueError:('empty keys are not allowed',)
 d["a"] = {"abc" : {u"": 1}}:ValueError:('empty keys are not allowed',)
 d["a"] = {"abc" : FailingMapping()}:NotImplementedError:()
 d["a"] = {"abc" : FailingMappingKey()}:NotImplementedError:()
 <<< Finished
 >>> Testing StringToChars using d["a"] = Mapping({%s : 1})
-d["a"] = Mapping({1 : 1}):TypeError:('object must be string',)
+d["a"] = Mapping({1 : 1}):TypeError:('expected str() or unicode() instance, but got int',)
 d["a"] = Mapping({u"\0" : 1}):TypeError:('expected string without null bytes',)
 d["a"] = Mapping({"\0" : 1}):TypeError:('expected string without null bytes',)
 <<< Finished
 >>> Testing StringToChars using d["a"] = Mapping({"abc" : {%s : 1}})
-d["a"] = Mapping({"abc" : {1 : 1}}):TypeError:('object must be string',)
+d["a"] = Mapping({"abc" : {1 : 1}}):TypeError:('expected str() or unicode() instance, but got int',)
 d["a"] = Mapping({"abc" : {u"\0" : 1}}):TypeError:('expected string without null bytes',)
 d["a"] = Mapping({"abc" : {"\0" : 1}}):TypeError:('expected string without null bytes',)
 <<< Finished
 >>> Testing StringToChars using d["a"] = Mapping({"abc" : Mapping({%s : 1})})
-d["a"] = Mapping({"abc" : Mapping({1 : 1})}):TypeError:('object must be string',)
+d["a"] = Mapping({"abc" : Mapping({1 : 1})}):TypeError:('expected str() or unicode() instance, but got int',)
 d["a"] = Mapping({"abc" : Mapping({u"\0" : 1})}):TypeError:('expected string without null bytes',)
 d["a"] = Mapping({"abc" : Mapping({"\0" : 1})}):TypeError:('expected string without null bytes',)
 <<< Finished
 >>> Testing *Iter* using d["a"] = Mapping({"abc" : %s})
-d["a"] = Mapping({"abc" : FailingIter()}):TypeError:('unable to convert to vim structure',)
+d["a"] = Mapping({"abc" : FailingIter()}):TypeError:('unable to convert FailingIter to vim structure',)
 d["a"] = Mapping({"abc" : FailingIterNext()}):NotImplementedError:()
 <<< Finished
 >>> Testing ConvertFromPyObject using d["a"] = Mapping({"abc" : %s})
-d["a"] = Mapping({"abc" : None}):TypeError:('unable to convert to vim structure',)
+d["a"] = Mapping({"abc" : None}):TypeError:('unable to convert NoneType to vim structure',)
 d["a"] = Mapping({"abc" : {"": 1}}):ValueError:('empty keys are not allowed',)
 d["a"] = Mapping({"abc" : {u"": 1}}):ValueError:('empty keys are not allowed',)
 d["a"] = Mapping({"abc" : FailingMapping()}):NotImplementedError:()
 d["a"] = Mapping({"abc" : FailingMappingKey()}):NotImplementedError:()
 <<< Finished
 >>> Testing *Iter* using d["a"] = %s
-d["a"] = FailingIter():TypeError:('unable to convert to vim structure',)
+d["a"] = FailingIter():TypeError:('unable to convert FailingIter to vim structure',)
 d["a"] = FailingIterNext():NotImplementedError:()
 <<< Finished
 >>> Testing ConvertFromPyObject using d["a"] = %s
-d["a"] = None:TypeError:('unable to convert to vim structure',)
+d["a"] = None:TypeError:('unable to convert NoneType to vim structure',)
 d["a"] = {"": 1}:ValueError:('empty keys are not allowed',)
 d["a"] = {u"": 1}:ValueError:('empty keys are not allowed',)
 d["a"] = FailingMapping():NotImplementedError:()
@@ -550,52 +550,52 @@ d["a"] = FailingMappingKey():NotImplementedError:()
 d.update(FailingMapping()):NotImplementedError:()
 d.update([FailingIterNext()]):NotImplementedError:()
 >>> Testing StringToChars using d.update({%s : 1})
-d.update({1 : 1}):TypeError:('object must be string',)
+d.update({1 : 1}):TypeError:('expected str() or unicode() instance, but got int',)
 d.update({u"\0" : 1}):TypeError:('expected string without null bytes',)
 d.update({"\0" : 1}):TypeError:('expected string without null bytes',)
 <<< Finished
 >>> Testing StringToChars using d.update({"abc" : {%s : 1}})
-d.update({"abc" : {1 : 1}}):TypeError:('object must be string',)
+d.update({"abc" : {1 : 1}}):TypeError:('expected str() or unicode() instance, but got int',)
 d.update({"abc" : {u"\0" : 1}}):TypeError:('expected string without null bytes',)
 d.update({"abc" : {"\0" : 1}}):TypeError:('expected string without null bytes',)
 <<< Finished
 >>> Testing StringToChars using d.update({"abc" : Mapping({%s : 1})})
-d.update({"abc" : Mapping({1 : 1})}):TypeError:('object must be string',)
+d.update({"abc" : Mapping({1 : 1})}):TypeError:('expected str() or unicode() instance, but got int',)
 d.update({"abc" : Mapping({u"\0" : 1})}):TypeError:('expected string without null bytes',)
 d.update({"abc" : Mapping({"\0" : 1})}):TypeError:('expected string without null bytes',)
 <<< Finished
 >>> Testing *Iter* using d.update({"abc" : %s})
-d.update({"abc" : FailingIter()}):TypeError:('unable to convert to vim structure',)
+d.update({"abc" : FailingIter()}):TypeError:('unable to convert FailingIter to vim structure',)
 d.update({"abc" : FailingIterNext()}):NotImplementedError:()
 <<< Finished
 >>> Testing ConvertFromPyObject using d.update({"abc" : %s})
-d.update({"abc" : None}):TypeError:('unable to convert to vim structure',)
+d.update({"abc" : None}):TypeError:('unable to convert NoneType to vim structure',)
 d.update({"abc" : {"": 1}}):ValueError:('empty keys are not allowed',)
 d.update({"abc" : {u"": 1}}):ValueError:('empty keys are not allowed',)
 d.update({"abc" : FailingMapping()}):NotImplementedError:()
 d.update({"abc" : FailingMappingKey()}):NotImplementedError:()
 <<< Finished
 >>> Testing StringToChars using d.update(Mapping({%s : 1}))
-d.update(Mapping({1 : 1})):TypeError:('object must be string',)
+d.update(Mapping({1 : 1})):TypeError:('expected str() or unicode() instance, but got int',)
 d.update(Mapping({u"\0" : 1})):TypeError:('expected string without null bytes',)
 d.update(Mapping({"\0" : 1})):TypeError:('expected string without null bytes',)
 <<< Finished
 >>> Testing StringToChars using d.update(Mapping({"abc" : {%s : 1}}))
-d.update(Mapping({"abc" : {1 : 1}})):TypeError:('object must be string',)
+d.update(Mapping({"abc" : {1 : 1}})):TypeError:('expected str() or unicode() instance, but got int',)
 d.update(Mapping({"abc" : {u"\0" : 1}})):TypeError:('expected string without null bytes',)
 d.update(Mapping({"abc" : {"\0" : 1}})):TypeError:('expected string without null bytes',)
 <<< Finished
 >>> Testing StringToChars using d.update(Mapping({"abc" : Mapping({%s : 1})}))
-d.update(Mapping({"abc" : Mapping({1 : 1})})):TypeError:('object must be string',)
+d.update(Mapping({"abc" : Mapping({1 : 1})})):TypeError:('expected str() or unicode() instance, but got int',)
 d.update(Mapping({"abc" : Mapping({u"\0" : 1})})):TypeError:('expected string without null bytes',)
 d.update(Mapping({"abc" : Mapping({"\0" : 1})})):TypeError:('expected string without null bytes',)
 <<< Finished
 >>> Testing *Iter* using d.update(Mapping({"abc" : %s}))
-d.update(Mapping({"abc" : FailingIter()})):TypeError:('unable to convert to vim structure',)
+d.update(Mapping({"abc" : FailingIter()})):TypeError:('unable to convert FailingIter to vim structure',)
 d.update(Mapping({"abc" : FailingIterNext()})):NotImplementedError:()
 <<< Finished
 >>> Testing ConvertFromPyObject using d.update(Mapping({"abc" : %s}))
-d.update(Mapping({"abc" : None})):TypeError:('unable to convert to vim structure',)
+d.update(Mapping({"abc" : None})):TypeError:('unable to convert NoneType to vim structure',)
 d.update(Mapping({"abc" : {"": 1}})):ValueError:('empty keys are not allowed',)
 d.update(Mapping({"abc" : {u"": 1}})):ValueError:('empty keys are not allowed',)
 d.update(Mapping({"abc" : FailingMapping()})):NotImplementedError:()
@@ -613,68 +613,68 @@ d.update(FailingMapping()):NotImplementedError:()
 d.update(FailingMappingKey()):NotImplementedError:()
 <<< Finished
 >>> Testing StringToChars using d.update(((%s, 0),))
-d.update(((1, 0),)):TypeError:('object must be string',)
+d.update(((1, 0),)):TypeError:('expected str() or unicode() instance, but got int',)
 d.update(((u"\0", 0),)):TypeError:('expected string without null bytes',)
 d.update((("\0", 0),)):TypeError:('expected string without null bytes',)
 <<< Finished
 >>> Testing StringToChars using d.update((("a", {%s : 1}),))
-d.update((("a", {1 : 1}),)):TypeError:('object must be string',)
+d.update((("a", {1 : 1}),)):TypeError:('expected str() or unicode() instance, but got int',)
 d.update((("a", {u"\0" : 1}),)):TypeError:('expected string without null bytes',)
 d.update((("a", {"\0" : 1}),)):TypeError:('expected string without null bytes',)
 <<< Finished
 >>> Testing StringToChars using d.update((("a", {"abc" : {%s : 1}}),))
-d.update((("a", {"abc" : {1 : 1}}),)):TypeError:('object must be string',)
+d.update((("a", {"abc" : {1 : 1}}),)):TypeError:('expected str() or unicode() instance, but got int',)
 d.update((("a", {"abc" : {u"\0" : 1}}),)):TypeError:('expected string without null bytes',)
 d.update((("a", {"abc" : {"\0" : 1}}),)):TypeError:('expected string without null bytes',)
 <<< Finished
 >>> Testing StringToChars using d.update((("a", {"abc" : Mapping({%s : 1})}),))
-d.update((("a", {"abc" : Mapping({1 : 1})}),)):TypeError:('object must be string',)
+d.update((("a", {"abc" : Mapping({1 : 1})}),)):TypeError:('expected str() or unicode() instance, but got int',)
 d.update((("a", {"abc" : Mapping({u"\0" : 1})}),)):TypeError:('expected string without null bytes',)
 d.update((("a", {"abc" : Mapping({"\0" : 1})}),)):TypeError:('expected string without null bytes',)
 <<< Finished
 >>> Testing *Iter* using d.update((("a", {"abc" : %s}),))
-d.update((("a", {"abc" : FailingIter()}),)):TypeError:('unable to convert to vim structure',)
+d.update((("a", {"abc" : FailingIter()}),)):TypeError:('unable to convert FailingIter to vim structure',)
 d.update((("a", {"abc" : FailingIterNext()}),)):NotImplementedError:()
 <<< Finished
 >>> Testing ConvertFromPyObject using d.update((("a", {"abc" : %s}),))
-d.update((("a", {"abc" : None}),)):TypeError:('unable to convert to vim structure',)
+d.update((("a", {"abc" : None}),)):TypeError:('unable to convert NoneType to vim structure',)
 d.update((("a", {"abc" : {"": 1}}),)):ValueError:('empty keys are not allowed',)
 d.update((("a", {"abc" : {u"": 1}}),)):ValueError:('empty keys are not allowed',)
 d.update((("a", {"abc" : FailingMapping()}),)):NotImplementedError:()
 d.update((("a", {"abc" : FailingMappingKey()}),)):NotImplementedError:()
 <<< Finished
 >>> Testing StringToChars using d.update((("a", Mapping({%s : 1})),))
-d.update((("a", Mapping({1 : 1})),)):TypeError:('object must be string',)
+d.update((("a", Mapping({1 : 1})),)):TypeError:('expected str() or unicode() instance, but got int',)
 d.update((("a", Mapping({u"\0" : 1})),)):TypeError:('expected string without null bytes',)
 d.update((("a", Mapping({"\0" : 1})),)):TypeError:('expected string without null bytes',)
 <<< Finished
 >>> Testing StringToChars using d.update((("a", Mapping({"abc" : {%s : 1}})),))
-d.update((("a", Mapping({"abc" : {1 : 1}})),)):TypeError:('object must be string',)
+d.update((("a", Mapping({"abc" : {1 : 1}})),)):TypeError:('expected str() or unicode() instance, but got int',)
 d.update((("a", Mapping({"abc" : {u"\0" : 1}})),)):TypeError:('expected string without null bytes',)
 d.update((("a", Mapping({"abc" : {"\0" : 1}})),)):TypeError:('expected string without null bytes',)
 <<< Finished
 >>> Testing StringToChars using d.update((("a", Mapping({"abc" : Mapping({%s : 1})})),))
-d.update((("a", Mapping({"abc" : Mapping({1 : 1})})),)):TypeError:('object must be string',)
+d.update((("a", Mapping({"abc" : Mapping({1 : 1})})),)):TypeError:('expected str() or unicode() instance, but got int',)
 d.update((("a", Mapping({"abc" : Mapping({u"\0" : 1})})),)):TypeError:('expected string without null bytes',)
 d.update((("a", Mapping({"abc" : Mapping({"\0" : 1})})),)):TypeError:('expected string without null bytes',)
 <<< Finished
 >>> Testing *Iter* using d.update((("a", Mapping({"abc" : %s})),))
-d.update((("a", Mapping({"abc" : FailingIter()})),)):TypeError:('unable to convert to vim structure',)
+d.update((("a", Mapping({"abc" : FailingIter()})),)):TypeError:('unable to convert FailingIter to vim structure',)
 d.update((("a", Mapping({"abc" : FailingIterNext()})),)):NotImplementedError:()
 <<< Finished
 >>> Testing ConvertFromPyObject using d.update((("a", Mapping({"abc" : %s})),))
-d.update((("a", Mapping({"abc" : None})),)):TypeError:('unable to convert to vim structure',)
+d.update((("a", Mapping({"abc" : None})),)):TypeError:('unable to convert NoneType to vim structure',)
 d.update((("a", Mapping({"abc" : {"": 1}})),)):ValueError:('empty keys are not allowed',)
 d.update((("a", Mapping({"abc" : {u"": 1}})),)):ValueError:('empty keys are not allowed',)
 d.update((("a", Mapping({"abc" : FailingMapping()})),)):NotImplementedError:()
 d.update((("a", Mapping({"abc" : FailingMappingKey()})),)):NotImplementedError:()
 <<< Finished
 >>> Testing *Iter* using d.update((("a", %s),))
-d.update((("a", FailingIter()),)):TypeError:('unable to convert to vim structure',)
+d.update((("a", FailingIter()),)):TypeError:('unable to convert FailingIter to vim structure',)
 d.update((("a", FailingIterNext()),)):NotImplementedError:()
 &l