External Editor is not started when clicking on the Stack Frames in Debugging panel

[API-Beast]

Godot version:
3.0.4

OS/device including version:
Windows 8.1

Issue description:
When setting Godot to use a external editor for editing scripts it won't run the external editor when clicking on the Stack Frames in the Debugger/Debugger tab.

It does run the editor when clicking on the entries in the stack trace of the Debugging/Error tab but many issues don't generate a stack trace in that tab. The built-in editor isn't opened either, forcing you to disable "Use External Editor" during debugging and re-enabling it once finished.

[rcorre]

Same issue on Linux using neovim as an external editor.
An example of an error that shows in the "Debugger/Debugger" tab but not in the "Debugging/Error" tab:

Invalid type in built-in function 'rand_range'. Cannot convert argument 2 from Nil to float.

[API-Beast]

Found two more situations in which neither the external editor nor the internal editor is launched:

• If the script is internal
• When using the "Make Function" setting in the Signal Editor

[rcorre]

- When using the "Make Function" setting in the Signal Editor

I don't have a computer with me, but I'm pretty sure that does launch the external editor for me. It doesn't generate the function, but I think I filed a separate issue about that. - Ryan

…

On July 12, 2018 8:10:09 AM PDT, Manuel Riecke ***@***.***> wrote: Found two more situations in which neither the external editor nor the internal editor is not launched: - If the script is internal the external editor won't launch - When using the "Make Function" setting in the Signal Editor

[akien-mga]

Is this still reproducible in the current master branch?

[rcorre]

@akien-mga yes, just tried 3.1.beta.custom_build.16d4021 with exec_path=st, exec_flags=nvim {file} +{line}. One of these shows up in "errors" every time I double-click a line in the stack:

E 0:00:04:0725   Condition ' _debug_parse_err_line >= 0 ' is true. returned: __null
  <C Source>     modules/gdscript/gdscript_editor.cpp:321 @ debug_get_stack_level_instance()

[KoBeWi]

Still valid in 3.2.2 rc1. Tested with VS Code, clicking Stack Frames doesn't even open the file.

The issues mentioned in #19838 (comment) are fixed.

EDIT:
Pic to show what doesn't work:

It opens in the internal editor.

[duane-r]

In v3.2.4.rc2, nothing happens when I click on a stack frame in the debugger tab -- neither the internal nor external editors open -- as long as the external editor is enabled.

[painttist]

Hi, in v4.2.2.rc, I am still having this issue.

After some digging around, I found out that this is related to ScriptEditor::edit inside editor>plugins>script_editor_plugin.cpp, in line 2308, there is an if statement that prevents debugger script being opened in an external editor unless an option DEBUG_WITH_EXTERNAL_EDITOR is checked. To my understanding, this toggleable option is currently only accessible by setting a shortcut for item "Debug with External Editor".

I suspect that there used to be a checkbox that could be used to toggle this setting but is now removed?

I would love to contribute further and submit a PR to fix this issue but I am uncertain if I should simply remove part of the if statement in line 2308 or should I attempt to add back a checkbox?