(terminal): the main process dies of heap corruption inside the bundled ConPTY

[devsuitup]

The main process dies with STATUS_HEAP_CORRUPTION (0xc0000374) inside a heap free called from the bundled ConPTY (useConptyDll). No JS error, no quit line in main.log — the app just disappears.

Measured (2026-10-01)

Five minidumps in %LOCALAPPDATA%\CrashDumps, same signature in all five:

Dump	Time	Process
electron.exe.1780	20:18:55	isolated live-test instance (repo worktree)
electron.exe.624	20:22:10	same
electron.exe.9256	20:27:14	same
electron.exe.22740	20:30:04	same
Switchboard.exe.4996	20:38:28	the installed v0.0.85, main process

• Fault ntdll+0x117eb5, exception 0xc0000374. Raw stack scan (no symbols, no debugger on the machine): ntdll+0x96be5, ntdll+0x12058a (heap free/validation) ← conpty.dll+0x6126, +0x60b0 ← conpty.node+0x5941, +0x981e, +0x8138 ← the V8 native call.
• conpty.dll is node-pty's bundled OpenConsole one (useConptyDll, v0.0.46), not the inbox ConPTY.
• The four isolated crashes happened during a live test that repeatedly opened the file panel's shell ((terminal): a resize while another terminal's WebGL context starts can paint it blank #353 investigation). The installed app crashed ~2 s after a second bash spawn ([shell] profile=auto … bash.exe at 20:38:06 and 20:38:09) and ~4 s after a renderer xterm.js Uncaught TypeError: Cannot read properties of undefined (reading 'dimensions').
• terminal-resize passes cols/rows unvalidated to resizePty (pty-ops.js ~37, a bare pty.resize in a try/catch that cannot catch a native fault); spawn sizes go through normalizePtySize (pty-size.js), resize does not.

Not known yet

Which operation (spawn, resize, close) frees the corrupted block. Next: symbolise the dumps (conpty.pdb ships in the node-pty prebuilds), and reproduce in an isolated instance by opening/closing panel shells quickly while resizing.