From adeccb46b3964afb23dd85baa4533f4b6f892fab Mon Sep 17 00:00:00 2001
From: CoolCat467 <52022020+CoolCat467@users.noreply.github.com>
Date: Tue, 24 Jun 2025 19:20:40 -0500
Subject: [PATCH 1/2] Allow dmypy suggest paths to contain drive letter colon
 in Windows machines Fixes #19335

---
 mypy/suggestions.py | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/mypy/suggestions.py b/mypy/suggestions.py
index 81eb20bd0ac3..56789b7f8dc2 100644
--- a/mypy/suggestions.py
+++ b/mypy/suggestions.py
@@ -27,6 +27,7 @@
 import itertools
 import json
 import os
+import sys
 from collections.abc import Iterator
 from contextlib import contextmanager
 from typing import Callable, NamedTuple, TypedDict, TypeVar, cast
@@ -549,12 +550,13 @@ def find_node(self, key: str) -> tuple[str, str, FuncDef]:
         # TODO: Also return OverloadedFuncDef -- currently these are ignored.
         node: SymbolNode | None = None
         if ":" in key:
-            if key.count(":") > 1:
+            platform_key_count = 2 if sys.platform == "win32" else 1
+            if key.count(":") > platform_key_count:
                 raise SuggestionFailure(
                     "Malformed location for function: {}. Must be either"
                     " package.module.Class.method or path/to/file.py:line".format(key)
                 )
-            file, line = key.split(":")
+            file, line = key.rsplit(":", 1)
             if not line.isdigit():
                 raise SuggestionFailure(f"Line number must be a number. Got {line}")
             line_number = int(line)

From 5281b06b11fdaf9bdf1af04d8928f646de3b4092 Mon Sep 17 00:00:00 2001
From: CoolCat467 <52022020+CoolCat467@users.noreply.github.com>
Date: Wed, 25 Jun 2025 21:27:34 -0500
Subject: [PATCH 2/2] Add logic explaination comment

Co-authored-by: Stanislav Terliakov <50529348+sterliakov@users.noreply.github.com>
---
 mypy/suggestions.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/mypy/suggestions.py b/mypy/suggestions.py
index 56789b7f8dc2..45aa5ade47a4 100644
--- a/mypy/suggestions.py
+++ b/mypy/suggestions.py
@@ -550,6 +550,10 @@ def find_node(self, key: str) -> tuple[str, str, FuncDef]:
         # TODO: Also return OverloadedFuncDef -- currently these are ignored.
         node: SymbolNode | None = None
         if ":" in key:
+            # A colon might be part of a drive name on Windows (like `C:/foo/bar`)
+            # and is also used as a delimiter between file path and lineno.
+            # If a colon is there for any of those reasons, it must be a file+line
+            # reference.
             platform_key_count = 2 if sys.platform == "win32" else 1
             if key.count(":") > platform_key_count:
                 raise SuggestionFailure(