Highlighting occurrences of symbol incorrectly highlights words, not symbols.

[therealpeterhua]

Environment data

• VS Code version: 1.30.1
• Extension version (available under the Extensions sidebar): 2018.12.1
• OS and version: MacOS
• Python version (& distribution if applicable, e.g. Anaconda): 2.7
• Type of virtual environment used (N/A | venv | virtualenv | conda | ...): N/A
• Relevant/affected Python packages and their versions: Only this one

Expected behaviour

Highlighting occurrences of a symbol (eg. activating the command "Trigger Symbol Highlight" from the palette, or moving into a word via the cursorRight command) should highlight all occurrences of a symbol, similar to the behavior in Javascript.

^ Here, as expected, the ASDF symbol is highlighted, but ASDF_QWER, being a different symbol, is not.

Actual behaviour

Highlighting symbol occurrences actually highlights occurrences of the word. If the word is present in more than one symbol, multiple symbols are highlighted.

^ Here, the `asdf` symbols are highlighted, but the `asdf` portion of `asdf_qwer` is also unexpectedly highlighted, even though it belongs to a different symbol.

Steps to reproduce:

1. Paste the following into an empty python file.

asdf = 3
asdf_qwe = 4
asdf = 7

2. Put cursor inside the asdf on the first line.
3. After a split second, the inconsistent highlighting will appear.

Doing these steps on a Javascript file will correctly highlight only the asdf symbols on lines 1 and 3.

[DonJayamanne]

Works just fine for me, see below:

Placing the cursor on the symbol highlights it.
Selecting the string will highlight all occurrences of the same string.

After a split second, the inconsistent highlighting will appear.

This indicate you must have some other extension that's causing this.

Please disable all other extensions and re-test.
Closing as I'm unable to replicate this, and we don't really control the highlighting of any symbols in the extension.

[therealpeterhua]

Ah, it's because I have the character _ in my word separators setting.

"editor.wordSeparators": ~!@#$%^&*()-=+[{]}\\|;:'\",.<>/?_"

It still seems a bug that adding a word separator breaks the symbol highlighting.
Judging by this section of the language extension guidelines I'd assumed this was handled by the language extension, but should I be filing this against vscode instead?