Code formatter duplicates contents on save when in extension development host

[matter123]

Type: LanguageService

Describe the bug

• OS and Version: Mac OS 10.14.15
• VS Code Version: 1.38.0-insider (ba69d8dcccaebbfaa94906503728eb7c3e45b9c1)
• C/C++ Extension Version: 0.25.0-insiders
• Other extensions you installed (and if the issue persists after disabling them): Issue persists after disabling all other extensions
• A clear and concise description of what the bug is.

When saving a new file when in extenstion development host window, the code formatter duplicates the file.

To Reproduce

1. Open an extension development host window
2. Create a new file
3. Set language to C++
4. Copy the following contents

void
foo()
;

5. Save
6. Observe that the file contains

void foo();
void foo();

Expected behavior

File contains just void foo();
Screenshots

Before Save	After Save

[sean-mcmanus]

Strange -- VS Code is sending us a didOpen and then sending us a didChange, which causes the file contents to get duplicated. I'll try filing a VS Code bug and see what they say.

microsoft/vscode#79252

It's not really a formatting bug, but an internal documentation corruption that the formatting makes visible.

[sean-mcmanus]

Should be fixed with 0.25.0.

[sean-mcmanus]

It wasn't actually fixed -- 0.25.1 should have the fix (when it's released).

[sean-mcmanus]

Should be fixed with 0.25.1 now.