VS Code on Windows is case sensitive to file paths when opening files while Debugging

[DonJayamanne]

Issue Type

Bug

Description

Currently we're working on a new debugger for the Python Extension

What we've idenfied is that when a breakpoint or exception is hit, VS Code opens another editor/copy for the same file on Windows.

Here's the scenario:

• Workspace = c:\Temp\python\debuggerTesting (note the upper case Ts)
• File being debugged one.py with the following contents:
  print(x)
• Note: x is undefined hence we expect the debugger to break at that line (unhandled exception).
• Open the file one.py (pin it, so it stays opened)
• Debug using the new experimental debugger
  Note: The debugger isn't public, hence you won't be able to replicate this. However we can provide the files through some other means.
• As soon as the debugger hits the breakpoint it opens another instance of the file one.py
  Now we have two editors opened, for the same file.
• However, hovering over the title of the second one.py (opened by debugger) we can see the path is c:\temp\python\debuggertesting\one.py.
  Note: Everything is in lower case (yes this is what's being returned by our debugger over the protocol).

Issue: VS Code on Windows, should realize the files are the same instead of opening a new editor.

VS Code Info

VS Code version: Code 1.20.1 (f88bbf9, 2018-02-13T15:23:28.607Z)
VS Code version: Code - Insiders 1.20.0-insider (eed7e19, 2018-01-30T09:40:57.870Z)
OS version: Darwin x64 17.4.0

System Info

Item	Value
CPUs	Intel(R) Core(TM) i7-7820HQ CPU @ 2.90GHz (8 x 2900)
Load (avg)	5, 4, 4
Memory (System)	16.00GB (1.06GB free)
Process Argv	/private/var/folders/22/0kj01mp12l3dsd1vw9vhfs6c0000gn/T/AppTranslocation/C4B4AE97-B9C0-4154-ADC9-76D932802595/d/Visual Studio Code - Insiders.app/Contents/MacOS/Electron
Screen Reader	no
VM	25%

Extensions (26)

Reproduces only with extensions: Specific to Python Extension

[weinand]

In general I agree: VS Code (on any platform) should ignore the case of a path when trying to map a path/URI to a workspace resource that lives on a case insensitive filesystem.
However, with the advent of remote file system providers and remote debugging it is a bit difficult to figure out whether a resource lives on a case insensitive filesystem (and needs a case-ignoring file matching).

/cc @bpasero @jrieken opinions?

[isidorn]

This is a general workbench issue
Duplicate #12448

As for the normalisation of drive letters going out to Debug Adapters, that will be tackled via #43959