bpo-21756: fix IDLE's "show surrounding parens" for multi-line statements

Lib/idlelib/hyperparser.py

@@ -23,7 +23,7 @@
 
 
 class HyperParser:
-    def __init__(self, editwin, index):
+    def __init__(self, editwin, index, *, end_at_eol=True):
         "To initialize, analyze the surroundings of the given index."
 
         self.editwin = editwin
@@ -34,13 +34,13 @@ def __init__(self, editwin, index):
         def index2line(index):
             return int(float(index))
         lno = index2line(text.index(index))
+        stopatindex = f"{lno}.end" if end_at_eol else "end-1c"
 
         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
+                startatindex = f"{startat}.0"
+                # We add a 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.
@@ -52,11 +52,10 @@ def index2line(index):
             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
+            startatindex = r[1] if r else "1.0"
+            if not end_at_eol and (r2 := text.tag_nextrange("console", index)):
+                stopatindex = f"{r2[0]}-1c"
+
             # 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.
@@ -119,10 +118,11 @@ def get_surrounding_brackets(self, openers='([{', mustclose=False):
         If the index given to the HyperParser is surrounded by a
         bracket defined in openers (or at least has one before it),
         return the indices of the opening bracket and the closing
-        bracket (or the end of line, whichever comes first).
+        bracket (or the end of line/file, whichever comes first).
 
-        If it is not surrounded by brackets, or the end of line comes
-        before the closing bracket and mustclose is True, returns None.
+        If it is not surrounded by brackets, or the end of line/file
+        comes before the closing bracket and mustclose is True, returns
+        None.
         """
 
         bracketinglevel = self.bracketing[self.indexbracket][1]

Lib/idlelib/parenmatch.py

@@ -75,8 +75,8 @@ def deactivate_restore(self):
 
     def flash_paren_event(self, event):
         "Handle editor 'show surrounding parens' event (menu or shortcut)."
-        indices = (HyperParser(self.editwin, "insert")
-                   .get_surrounding_brackets())
+        hp = HyperParser(self.editwin, "insert", end_at_eol=False)
+        indices = hp.get_surrounding_brackets()
         self.finish_paren_event(indices)
         return "break"
 

Misc/NEWS.d/next/IDLE/2020-06-09-10-47-33.bpo-21756.auszVR.rst

@@ -0,0 +1 @@
+Fixed IDLE's "show surrounding parens" for multi-line statements.