Microsoft Pinyin (Chinese Input) Fails to Show Candidate List for Vowel-Initial Words

[lycc193]

Does this issue occur when all extensions are disabled?: Yes

• VS Code Version: 1.102.0-insider
• OS Version: Windows 10 Pro 22H2 19045.5854
• Input Method:​​ System-default ​​Microsoft Pinyin IME
• IME Mode:​​ ​​Legacy Compatibility Mode​​ enabled

Reproducible in: VS Code main application, also reproducible in the official edit-context demo

Trigger:​​ Typing words where the ​​first letter is a vowel (a, e, i, o, u, v)​​.

Symptoms:

• Candidate List Not Displayed: The candidate word selection panel does not appear.
• Number Key Selection Disabled: Pressing number keys (1, 2, 3, 4, etc.) does not select the corresponding candidate word.

Workaround: The only available action is pressing the Space key to select the first candidate word.

Expected Behavior:

• The candidate word selection panel should appear normally when typing vowel-initial words.
• Users should be able to select candidate words using number keys (1-9), as expected.

Reproduction Steps:

1. Ensure Microsoft Pinyin IME is active with Legacy Compatibility Mode enabled.

2. In VS Code (or its edit-context demo), attempt to type a Chinese word starting with a vowel (e.g., ai for 爱, ou for 偶).

3. Observe that the candidate list fails to appear.

4. Attempt to press number keys (e.g., 1, 2) while no candidate list is visible; note that the expected candidate is not selected.

Validation:

• Expected: This behavior (failure to show candidate list & use number keys) is consistently reproducible in VS Code and its official edit-context demo.

• Works Elsewhere: In other applications (e.g., Notepad, web browsers), typing vowel-initial words correctly displays the candidate list and allows number key selection.

[aiday-mar]

Hi thanks for filing this issue. This looks like it is a duplicate of #251518. Do you see this issue happen when you move to the newer Chinese Pinyin IME version so with legacy compatibility mode disabled?

[lycc193]

After testing, this issue does not occur when using the new version. As for why I still use the old version and some related questions, I will post them in the issue mentioned above.