updated for version 7.4.107

Problem:    Python: When vim.eval() encounters a Vim error, a try/catch in the
	    Python code doesn't catch it. (Yggdroot Chen)
Solution:   Throw exceptions on errors in vim.eval(). (ZyX)

Author: brammool

src/ex_eval.c

@@ -320,6 +320,17 @@ free_msglist(l)
     }
 }
 
+/*
+ * Free global "*msg_list" and the messages it contains, then set "*msg_list"
+ * to NULL.
+ */
+    void
+free_global_msglist()
+{
+    free_msglist(*msg_list);
+    *msg_list = NULL;
+}
+
 /*
  * Throw the message specified in the call to cause_errthrow() above as an
  * error exception.  If cstack is NULL, postpone the throw until do_cmdline()
@@ -410,66 +421,41 @@ do_intthrow(cstack)
     return TRUE;
 }
 
-
 /*
- * Throw a new exception.  Return FAIL when out of memory or it was tried to
- * throw an illegal user exception.  "value" is the exception string for a user
- * or interrupt exception, or points to a message list in case of an error
- * exception.
+ * Get an exception message that is to be stored in current_exception->value.
  */
-    static int
-throw_exception(value, type, cmdname)
+    char_u *
+get_exception_string(value, type, cmdname, should_free)
     void	*value;
     int		type;
     char_u	*cmdname;
+    int		*should_free;
 {
-    except_T	*excp;
-    char_u	*p, *mesg, *val;
+    char_u	*ret, *mesg;
     int		cmdlen;
-
-    /*
-     * Disallow faking Interrupt or error exceptions as user exceptions.  They
-     * would be treated differently from real interrupt or error exceptions when
-     * no active try block is found, see do_cmdline().
-     */
-    if (type == ET_USER)
-    {
-	if (STRNCMP((char_u *)value, "Vim", 3) == 0 &&
-		(((char_u *)value)[3] == NUL || ((char_u *)value)[3] == ':' ||
-		 ((char_u *)value)[3] == '('))
-	{
-	    EMSG(_("E608: Cannot :throw exceptions with 'Vim' prefix"));
-	    goto fail;
-	}
-    }
-
-    excp = (except_T *)alloc((unsigned)sizeof(except_T));
-    if (excp == NULL)
-	goto nomem;
+    char_u	*p, *val;
 
     if (type == ET_ERROR)
     {
-	/* Store the original message and prefix the exception value with
-	 * "Vim:" or, if a command name is given, "Vim(cmdname):". */
-	excp->messages = (struct msglist *)value;
-	mesg = excp->messages->throw_msg;
+	*should_free = FALSE;
+	mesg = ((struct msglist *)value)->throw_msg;
 	if (cmdname != NULL && *cmdname != NUL)
 	{
 	    cmdlen = (int)STRLEN(cmdname);
-	    excp->value = vim_strnsave((char_u *)"Vim(",
+	    ret = vim_strnsave((char_u *)"Vim(",
 					   4 + cmdlen + 2 + (int)STRLEN(mesg));
-	    if (excp->value == NULL)
-		goto nomem;
-	    STRCPY(&excp->value[4], cmdname);
-	    STRCPY(&excp->value[4 + cmdlen], "):");
-	    val = excp->value + 4 + cmdlen + 2;
+	    if (ret == NULL)
+		return ret;
+	    STRCPY(&ret[4], cmdname);
+	    STRCPY(&ret[4 + cmdlen], "):");
+	    val = ret + 4 + cmdlen + 2;
 	}
 	else
 	{
-	    excp->value = vim_strnsave((char_u *)"Vim:", 4 + (int)STRLEN(mesg));
-	    if (excp->value == NULL)
-		goto nomem;
-	    val = excp->value + 4;
+	    ret = vim_strnsave((char_u *)"Vim:", 4 + (int)STRLEN(mesg));
+	    if (ret == NULL)
+		return ret;
+	    val = ret + 4;
 	}
 
 	/* msg_add_fname may have been used to prefix the message with a file
@@ -506,14 +492,65 @@ throw_exception(value, type, cmdname)
 	}
     }
     else
-	excp->value = value;
+    {
+	*should_free = FALSE;
+	ret = (char_u *) value;
+    }
+
+    return ret;
+}
+
+
+/*
+ * Throw a new exception.  Return FAIL when out of memory or it was tried to
+ * throw an illegal user exception.  "value" is the exception string for a
+ * user or interrupt exception, or points to a message list in case of an
+ * error exception.
+ */
+    static int
+throw_exception(value, type, cmdname)
+    void	*value;
+    int		type;
+    char_u	*cmdname;
+{
+    except_T	*excp;
+    int		should_free;
+
+    /*
+     * Disallow faking Interrupt or error exceptions as user exceptions.  They
+     * would be treated differently from real interrupt or error exceptions
+     * when no active try block is found, see do_cmdline().
+     */
+    if (type == ET_USER)
+    {
+	if (STRNCMP((char_u *)value, "Vim", 3) == 0
+		&& (((char_u *)value)[3] == NUL || ((char_u *)value)[3] == ':'
+		    || ((char_u *)value)[3] == '('))
+	{
+	    EMSG(_("E608: Cannot :throw exceptions with 'Vim' prefix"));
+	    goto fail;
+	}
+    }
+
+    excp = (except_T *)alloc((unsigned)sizeof(except_T));
+    if (excp == NULL)
+	goto nomem;
+
+    if (type == ET_ERROR)
+	/* Store the original message and prefix the exception value with
+	 * "Vim:" or, if a command name is given, "Vim(cmdname):". */
+	excp->messages = (struct msglist *)value;
+
+    excp->value = get_exception_string(value, type, cmdname, &should_free);
+    if (excp->value == NULL && should_free)
+	goto nomem;
 
     excp->type = type;
     excp->throw_name = vim_strsave(sourcing_name == NULL
 					      ? (char_u *)"" : sourcing_name);
     if (excp->throw_name == NULL)
     {
-	if (type == ET_ERROR)
+	if (should_free)
 	    vim_free(excp->value);
 	goto nomem;
     }
@@ -2033,10 +2070,7 @@ leave_cleanup(csp)
 	/* If an error was about to be converted to an exception when
 	 * enter_cleanup() was called, free the message list. */
 	if (msg_list != NULL)
-	{
-	    free_msglist(*msg_list);
-	    *msg_list = NULL;
-	}
+	    free_global_msglist();
     }
 
     /*

src/if_py_both.h

@@ -566,6 +566,28 @@ VimTryEnd(void)
 	PyErr_SetNone(PyExc_KeyboardInterrupt);
 	return -1;
     }
+    else if (msg_list != NULL && *msg_list != NULL)
+    {
+	int	should_free;
+	char_u	*msg;
+
+	msg = get_exception_string(*msg_list, ET_ERROR, NULL, &should_free);
+
+	if (msg == NULL)
+	{
+	    PyErr_NoMemory();
+	    return -1;
+	}
+
+	PyErr_SetVim((char *) msg);
+
+	free_global_msglist();
+
+	if (should_free)
+	    vim_free(msg);
+
+	return -1;
+    }
     else if (!did_throw)
 	return (PyErr_Occurred() ? -1 : 0);
     /* Python exception is preferred over vim one; unlikely to occur though */

src/proto/ex_eval.pro

@@ -4,8 +4,10 @@ void update_force_abort __ARGS((void));
 int should_abort __ARGS((int retcode));
 int aborted_in_try __ARGS((void));
 int cause_errthrow __ARGS((char_u *mesg, int severe, int *ignore));
+void free_global_msglist __ARGS((void));
 void do_errthrow __ARGS((struct condstack *cstack, char_u *cmdname));
 int do_intthrow __ARGS((struct condstack *cstack));
+char_u *get_exception_string __ARGS((void *value, int type, char_u *cmdname, int *should_free));
 void discard_current_exception __ARGS((void));
 void report_make_pending __ARGS((int pending, void *value));
 void report_resume_pending __ARGS((int pending, void *value));

src/testdir/test86.in

@@ -179,6 +179,32 @@ EOF
 :unlockvar! l
 :"
 :" Function calls
+py << EOF
+import sys
+def ee(expr, g=globals(), l=locals()):
+    try:
+        exec(expr, g, l)
+    except:
+        ei = sys.exc_info()
+        msg = sys.exc_info()[0].__name__ + ':' + repr(sys.exc_info()[1].args)
+        msg = msg.replace('TypeError:(\'argument 1 ', 'TypeError:(\'')
+        if expr.find('None') > -1:
+            msg = msg.replace('TypeError:(\'iteration over non-sequence\',)',
+                              'TypeError:("\'NoneType\' object is not iterable",)')
+        if expr.find('FailingNumber') > -1:
+            msg = msg.replace(', not \'FailingNumber\'', '').replace('"', '\'')
+            msg = msg.replace('TypeError:(\'iteration over non-sequence\',)',
+                              'TypeError:("\'FailingNumber\' object is not iterable",)')
+        if msg.find('(\'\'') > -1 or msg.find('(\'can\'t') > -1:
+            msg = msg.replace('(\'', '("').replace('\',)', '",)')
+        if expr == 'fd(self=[])':
+            # HACK: PyMapping_Check changed meaning
+            msg = msg.replace('AttributeError:(\'keys\',)',
+                              'TypeError:(\'unable to convert list to vim dictionary\',)')
+        vim.current.buffer.append(expr + ':' + msg)
+    else:
+        vim.current.buffer.append(expr + ':NOT FAILED')
+EOF
 :fun New(...)
 :   return ['NewStart']+a:000+['NewEnd']
 :endfun
@@ -193,18 +219,10 @@ EOF
 :$put =string(l)
 :py l.extend([l[0].name])
 :$put =string(l)
-:try
-:   py l[1](1, 2, 3)
-:catch
-:   $put =v:exception[:16]
-:endtry
+:py ee('l[1](1, 2, 3)')
 :py f=l[0]
 :delfunction New
-:try
-:   py f(1, 2, 3)
-:catch
-:   $put =v:exception[:16]
-:endtry
+:py ee('f(1, 2, 3)')
 :if has('float')
 :   let l=[0.0]
 :   py l=vim.bindeval('l')
@@ -216,7 +234,6 @@ EOF
 :let messages=[]
 :delfunction DictNew
 py <<EOF
-import sys
 d=vim.bindeval('{}')
 m=vim.bindeval('messages')
 def em(expr, g=globals(), l=locals()):
@@ -323,6 +340,7 @@ EOF
 :py l[0] = t.t > 8  # check if the background thread is working
 :py del time
 :py del threading
+:py del t
 :$put =string(l)
 :"
 :" settrace
@@ -882,29 +900,6 @@ EOF
 :fun D()
 :endfun
 py << EOF
-def ee(expr, g=globals(), l=locals()):
-    try:
-        exec(expr, g, l)
-    except:
-        ei = sys.exc_info()
-        msg = sys.exc_info()[0].__name__ + ':' + repr(sys.exc_info()[1].args)
-        msg = msg.replace('TypeError:(\'argument 1 ', 'TypeError:(\'')
-        if expr.find('None') > -1:
-            msg = msg.replace('TypeError:(\'iteration over non-sequence\',)',
-                              'TypeError:("\'NoneType\' object is not iterable",)')
-        if expr.find('FailingNumber') > -1:
-            msg = msg.replace(', not \'FailingNumber\'', '').replace('"', '\'')
-            msg = msg.replace('TypeError:(\'iteration over non-sequence\',)',
-                              'TypeError:("\'FailingNumber\' object is not iterable",)')
-        if msg.find('(\'\'') > -1 or msg.find('(\'can\'t') > -1:
-            msg = msg.replace('(\'', '("').replace('\',)', '",)')
-        if expr == 'fd(self=[])':
-            # HACK: PyMapping_Check changed meaning
-            msg = msg.replace('AttributeError:(\'keys\',)',
-                              'TypeError:(\'unable to convert list to vim dictionary\',)')
-        cb.append(expr + ':' + msg)
-    else:
-        cb.append(expr + ':NOT FAILED')
 d = vim.Dictionary()
 ned = vim.Dictionary(foo='bar', baz='abcD')
 dl = vim.Dictionary(a=1)
@@ -1276,6 +1271,7 @@ ee('Exe("throw \'def\'")')
 ee('vim.eval("Exe(\'throw \'\'ghi\'\'\')")')
 ee('vim.eval("Exe(\'echoerr \'\'jkl\'\'\')")')
 ee('vim.eval("Exe(\'xxx_non_existent_command_xxx\')")')
+ee('vim.eval("xxx_unknown_function_xxx()")')
 ee('vim.bindeval("Exe(\'xxx_non_existent_command_xxx\')")')
 del Exe
 EOF

src/testdir/test86.ok

@@ -53,8 +53,8 @@ None
 [function('New'), function('DictNew'), 'NewStart', 1, 2, 3, 'NewEnd']
 [function('New'), function('DictNew'), 'NewStart', 1, 2, 3, 'NewEnd', 'DictNewStart', 1, 2, 3, 'DictNewEnd', {'a': 'b'}]
 [function('New'), function('DictNew'), 'NewStart', 1, 2, 3, 'NewEnd', 'DictNewStart', 1, 2, 3, 'DictNewEnd', {'a': 'b'}, 'New']
-Vim(python):E725:
-Vim(python):E117:
+l[1](1, 2, 3):error:('Vim:E725: Calling dict function without Dictionary: DictNew',)
+f(1, 2, 3):error:('Vim:E117: Unknown function: New',)
 [0.0, 0.0]
 KeyError
 TypeError
@@ -1197,6 +1197,7 @@ Exe("throw 'def'"):error:('def',)
 vim.eval("Exe('throw ''ghi''')"):error:('ghi',)
 vim.eval("Exe('echoerr ''jkl''')"):error:('Vim(echoerr):jkl',)
 vim.eval("Exe('xxx_non_existent_command_xxx')"):error:('Vim:E492: Not an editor command: xxx_non_existent_command_xxx',)
+vim.eval("xxx_unknown_function_xxx()"):error:('Vim:E117: Unknown function: xxx_unknown_function_xxx',)
 vim.bindeval("Exe('xxx_non_existent_command_xxx')"):error:('Vim:E492: Not an editor command: xxx_non_existent_command_xxx',)
 Caught KeyboardInterrupt
 Running :put