starred/terminal
1
0
Fork 0
mirror of https://github.com/microsoft/terminal.git synced 2026-02-03 21:25:34 +00:00
Code Issues 19.0k Packages Projects Releases 20 Wiki Activity

SetConsoleWindowInfo + cmd/powershell yields invisible prompt #375

New Issue
Open
opened 2026-01-30 21:50:18 +00:00 by claunia · 0 comments
claunia commented 2026-01-30 21:50:18 +00:00
Owner
Copy Link

Originally created by @rprichard on GitHub (Sep 17, 2018).

  • Your Windows build number: [Version 10.0.17760.1]

What you're doing and what's happening:

Steps:

  1. Create a new console.
  2. In the new console, reduce the height of the console window using SetConsoleWindowInfo.
  3. Spawn cmd.exe or powershell.exe

The prompt appears in the console buffer, but the console scrolls down so that the cursor and the prompt are both invisible:

invisible-prompt

What's wrong / what should be happening instead:

The window should remain at the top of the console buffer, so that the cursor and prompt are still visible.

This issue explains at least some of the winpty breakage reported at https://github.com/Microsoft/vscode/issues/57803. Any time the console window moves down, winpty assumes that something has been written to the bottommost line of the window. (e.g. In this case, it sees a window full of blank lines.) The console window is blank, so the winpty terminal output is also blank.

The problem doesn't affect the Python 3.7 REPL. I haven't tested other command-line shells/interpreters.

Test case:

#include <windows.h>
#include <stdio.h>
#include <string.h>
#include <process.h>

static int childProcess() {
    // Divide the console window height in half using SetConsoleWindowInfo.
    // Using SetConsoleScreenBufferInfoEx instead seems to avoid this problem,
    // but it has other problems.
    HANDLE conout = GetStdHandle(STD_OUTPUT_HANDLE);
    CONSOLE_SCREEN_BUFFER_INFOEX info = { sizeof(info) };
    GetConsoleScreenBufferInfoEx(conout, &info);
    const int h = info.srWindow.Bottom - info.srWindow.Top + 1;

    // Make the console buffer smaller so the problem is more apparent.
    SetConsoleScreenBufferSize(conout, COORD {
        (SHORT)(info.srWindow.Right - info.srWindow.Left + 1),
        (SHORT)(h + 100),
    });

    // Reduce the window height by half.
    info.srWindow.Bottom = info.srWindow.Top + h / 2 - 1;
    SetConsoleWindowInfo(conout, TRUE, &info.srWindow);

    // At this point, the console window is still at the top of the buffer.

    // Run cmd.exe (or powershell.exe). The shell prompt appears at the
    // expected place in the console buffer, but the window is moved below the
    // prompt and below the cursor, making them invisible.
    _execl("C:\\Windows\\system32\\cmd.exe", "C:\\Windows\\system32\\cmd.exe", NULL);
    return 0;
}

int main(int argc, char *argv[]) {
    if (argc == 2 && !strcmp(argv[1], "child")) {
        return childProcess();
    }

    char cmdline[4096];
    snprintf(cmdline, sizeof(cmdline), "\"%s\" child", argv[0]);
    STARTUPINFOA sui = { sizeof(sui) };
    PROCESS_INFORMATION pi = {};
    CreateProcessA(argv[0], cmdline, nullptr, nullptr, TRUE,
                   CREATE_NEW_CONSOLE, nullptr, nullptr, &sui, &pi);
    return 0;
}
Originally created by @rprichard on GitHub (Sep 17, 2018). * Your Windows build number: [Version 10.0.17760.1] ## What you're doing and what's happening: Steps: 1. Create a new console. 2. In the new console, reduce the height of the console window using `SetConsoleWindowInfo`. 3. Spawn `cmd.exe` or `powershell.exe` The prompt appears in the console buffer, but the console scrolls down so that the cursor and the prompt are both invisible: ![invisible-prompt](https://user-images.githubusercontent.com/1572855/45613504-7a16d480-ba1b-11e8-8cab-839353e92ae5.png) ## What's wrong / what should be happening instead: The window should remain at the top of the console buffer, so that the cursor and prompt are still visible. This issue explains at least some of the winpty breakage reported at https://github.com/Microsoft/vscode/issues/57803. Any time the console window moves down, winpty assumes that something has been written to the bottommost line of the window. (e.g. In this case, it sees a window full of blank lines.) The console window is blank, so the winpty terminal output is also blank. The problem doesn't affect the Python 3.7 REPL. I haven't tested other command-line shells/interpreters. ## Test case: ```c++ #include <windows.h> #include <stdio.h> #include <string.h> #include <process.h> static int childProcess() { // Divide the console window height in half using SetConsoleWindowInfo. // Using SetConsoleScreenBufferInfoEx instead seems to avoid this problem, // but it has other problems. HANDLE conout = GetStdHandle(STD_OUTPUT_HANDLE); CONSOLE_SCREEN_BUFFER_INFOEX info = { sizeof(info) }; GetConsoleScreenBufferInfoEx(conout, &info); const int h = info.srWindow.Bottom - info.srWindow.Top + 1; // Make the console buffer smaller so the problem is more apparent. SetConsoleScreenBufferSize(conout, COORD { (SHORT)(info.srWindow.Right - info.srWindow.Left + 1), (SHORT)(h + 100), }); // Reduce the window height by half. info.srWindow.Bottom = info.srWindow.Top + h / 2 - 1; SetConsoleWindowInfo(conout, TRUE, &info.srWindow); // At this point, the console window is still at the top of the buffer. // Run cmd.exe (or powershell.exe). The shell prompt appears at the // expected place in the console buffer, but the window is moved below the // prompt and below the cursor, making them invisible. _execl("C:\\Windows\\system32\\cmd.exe", "C:\\Windows\\system32\\cmd.exe", NULL); return 0; } int main(int argc, char *argv[]) { if (argc == 2 && !strcmp(argv[1], "child")) { return childProcess(); } char cmdline[4096]; snprintf(cmdline, sizeof(cmdline), "\"%s\" child", argv[0]); STARTUPINFOA sui = { sizeof(sui) }; PROCESS_INFORMATION pi = {}; CreateProcessA(argv[0], cmdline, nullptr, nullptr, TRUE, CREATE_NEW_CONSOLE, nullptr, nullptr, &sui, &pi); return 0; } ```
claunia added the Product-ConhostResolution-Duplicate labels 2026-01-30 21:50:18 +00:00
Sign in to join this conversation.
No Branch/Tag Specified
Branches Tags
Labels
Clear labels
⛺ Reserved
A11yCO
A11yMAS
A11ySev1
A11ySev2
A11ySev3
A11yTTValidated
A11yUsable
A11yVoiceAccess
A11yWCAG
Area-Accessibility
Area-AtlasEngine
Area-AzureShell
Area-Build
Area-Build
Area-Chat
Area-CmdPal
Area-CodeHealth
Area-Commandline
Area-CookedRead
Area-DefApp
Area-Extensibility
Area-Fonts
Area-GroupPolicy
Area-i18n
Area-Input
Area-Interaction
Area-Interop
Area-Localization
Area-Output
Area-Performance
Area-Portable
Area-Quality
Area-Remoting
Area-Rendering
Area-Schema
Area-Server
Area-Settings
Area-SettingsUI
Area-ShellExtension
Area-ShellExtension
Area-ShellExtension
Area-Suggestions
Area-Suggestions
Area-TerminalConnection
Area-TerminalControl
Area-Theming
Area-UserInterface
Area-VT
Area-Windowing
Area-WPFControl
AutoMerge
Blocking-Ingestion
Culprit-Centennial
Culprit-WinUI
Disability-All
Disability-Blind
Disability-LowVision
Disability-Mobility
External-Blocked-WinUI3
Fixed
Gathering-Data
good first issue
HCL-E+D
HCL-WindowsTerminal
Help Wanted
Impact-Compatibility
Impact-Compliance
Impact-Correctness
Impact-Visual
In-PR
InclusionBacklog
InclusionBacklog-Windows TerminalWin32
InclusionCommitted-202206
Issue-Bug
Issue-Docs
Issue-Feature
Issue-Feature
Issue-Question
Issue-Samples
Issue-Scenario
Issue-Task
Needs-Attention
Needs-Author-Feedback
Needs-Bisect
Needs-Discussion
Needs-Repro
Needs-Tag-Fix
Needs-Tag-Fix
Needs-Triage
No-Recent-Activity
Priority-0
Priority-1
Priority-2
Priority-3
Product-Cmd.exe
Product-Colortool
Product-Colortool
Product-Colortool
Product-Conhost
Product-Conpty
Product-Meta
Product-Powershell
Product-Terminal
Product-WSL
pull-request
Mirrored from GitHub Pull Request
 Resolution-Answered
Resolution-By-Design
Resolution-Duplicate
Resolution-External
Resolution-Fix-Available
Resolution-Fix-Committed
Resolution-No-Repro
Resolution-Won't-Fix
Severity-Blocking
Severity-Crash
Severity-DataLoss
spam
this-will-be-a-breaking-change
Tracking-External
WindowsTerminal_Win32
Work-Item
zAskModeBug
zInbox-Bug
No Label Product-Conhost Resolution-Duplicate
Milestone
No items
No Milestone
Projects
Clear projects
No project
Assignees
Clear assignees
claunia
No Assignees
1 Participants
Notifications
Due Date
No due date set.
Dependencies

No dependencies set.

Reference: starred/terminal#375
Delete Branch "%!s()"

Deleting a branch is permanent. Although the deleted branch may continue to exist for a short time before it actually gets removed, it CANNOT be undone in most cases. Continue?