gh-124451: Fix where IDLE starts parsing

Lib/idlelib/hyperparser.py

@@ -31,44 +31,20 @@ def __init__(self, editwin, index):
 
         parser = pyparse.Parser(editwin.indentwidth, editwin.tabwidth)
 
+        startatindex = text.index('iomark')
+
         def index2line(index):
             return int(float(index))
         lno = index2line(text.index(index))
 
-        if not editwin.prompt_last_line:
-            for context in editwin.num_context_lines:
-                startat = max(lno - context, 1)
-                startatindex = repr(startat) + ".0"
-                stopatindex = "%d.end" % lno
-                # We add the newline because PyParse requires a newline
-                # at end. We add a space so that index won't be at end
-                # of line, so that its status will be the same as the
-                # char before it, if should.
-                parser.set_code(text.get(startatindex, stopatindex)+' \n')
-                bod = parser.find_good_parse_start(
-                          editwin._build_char_in_string_func(startatindex))
-                if bod is not None or startat == 1:
-                    break
-            parser.set_lo(bod or 0)
-        else:
-            r = text.tag_prevrange("console", index)
-            if r:
-                startatindex = r[1]
-            else:
-                startatindex = "1.0"
-            stopatindex = "%d.end" % lno
-            # We add the newline because PyParse requires it. We add a
-            # space so that index won't be at end of line, so that its
-            # status will be the same as the char before it, if should.
-            parser.set_code(text.get(startatindex, stopatindex)+' \n')
-            parser.set_lo(0)
-
-        # We want what the parser has, minus the last newline and space.
-        self.rawtext = parser.code[:-2]
+        statement = text.get(startatindex, '%d.end' % lno)
+        self.rawtext = statement
+        parser.set_code(statement + '\n')
+
         # Parser.code apparently preserves the statement we are in, so
         # that stopatindex can be used to synchronize the string with
         # the text box indices.
-        self.stopatindex = stopatindex
+        self.stopatindex = '%d.end' % lno
         self.bracketing = parser.get_last_stmt_bracketing()
         # find which pairs of bracketing are openers. These always
         # correspond to a character of rawtext.

Lib/idlelib/idle_test/mock_tk.py

@@ -111,6 +111,7 @@ def __init__(self, master=None, cnf={}, **kw):
         There are just a few Text-only options that affect text behavior.
         '''
         self.data = ['', '\n']
+        self.marks = {}
 
     def index(self, index):
         "Return string version of index decoded according to current text."
@@ -144,6 +145,8 @@ def _decode(self, index, endflag=0):
             return lastline, len(self.data[lastline]) - 1
         elif index == 'end':
             return self._endex(endflag)
+        elif '.' not in index:
+            return self._decode(self.marks[index], endflag)
 
         line, char = index.split('.')
         line = int(line)
@@ -271,7 +274,7 @@ def compare(self, index1, op, index2):
 
     def mark_set(self, name, index):
         "Set mark *name* before the character at index."
-        pass
+        self.marks[name] = index
 
     def mark_unset(self, *markNames):
         "Delete all marks in markNames."

Lib/idlelib/idle_test/test_calltip.py

@@ -281,6 +281,7 @@ class mock_Shell:
     "Return mock sufficient to pass to hyperparser."
     def __init__(self, text):
         text.tag_prevrange = Mock(return_value=None)
+        text.mark_set('iomark', '1.0')
         self.text = text
         self.prompt_last_line = ">>> "
         self.indentwidth = 4