fix: keyTap throws "Invalid key code" for valid keys due to dangling pointer

[ssxv]

Issue: #789

Description

robot.keyTap("tab") and other valid multi-character key names throw Error: Invalid key code specified due to a dangling pointer bug in keyTapWrapper.

Root Cause

In src/robotjs.cc, the keyTapWrapper function was doing this:

Napi::String kstr(env, info[0].ToString());
k = kstr.Utf8Value().c_str();

kstr.Utf8Value() returns a temporary std::string. Taking .c_str() from it gives a raw pointer that becomes invalid as soon as the temporary is destroyed - at the end of that same statement. By the time k is passed to CheckKeyCodes(), it is a dangling pointer pointing to freed memory, causing the key name lookup against the key_names table to fail unpredictably.

This is a non-deterministic bug - it may work in some environments depending on whether the freed memory has been overwritten.

Fix

Changed keyTapWrapper to store the string in a named std::string that lives for the full function scope, matching the pattern already used in keyToggleWrapper:

std::string kstr = info[0].As<Napi::String>();
k = kstr.c_str();

Files Changed

• robotjs.cc - keyTapWrapper function only

Testing

Verified that robot.keyTap("tab") and other named keys (enter, backspace, escape, etc.) no longer throw Invalid key code specified after the fix.

[ssxv]

@octalmage

Please check this. Key Tap isn't working. Its one of basic functionalities of robotjs which is breaking In v0.7.0

[octalmage]

Thanks for the PR! I had fixed this in #784 and just cherry-picked the commit into master (as well as a few other build fixes). I will work on getting a fix deployed to npm!

[octalmage]

robotjs@0.7.1 deployed to npm which resolve this issue, thanks again!!