starred/terminal
1
0
Fork 0
mirror of https://github.com/microsoft/terminal.git synced 2026-02-04 05:35:20 +00:00
Code Issues 19.0k Packages Projects Releases 20 Wiki Activity

Console background color has strange behavior when changed from a program #11267

New Issue
Closed
opened 2026-01-31 02:42:56 +00:00 by claunia · 4 comments
claunia commented 2026-01-31 02:42:56 +00:00
Owner
Copy Link

Originally created by @jgonzalezdr on GitHub (Nov 3, 2020).

Environment

Windows build number: Microsoft Windows [Versión 10.0.18363.1139]
Windows Terminal version (if applicable): 1.3.2651.0

Any other software?

Steps to reproduce

Take a program that changes the console background using Win32 API calls like the following, and execute it several times:

#include "windows.h"

void WriteToConsole( HANDLE handle, const char* text )
{
    WriteConsole( handle, text, (DWORD) strlen(text), NULL, NULL );
}

void main( int argc, const char* argv[] )
{
    HANDLE handle =  GetStdHandle( STD_OUTPUT_HANDLE );
    CONSOLE_SCREEN_BUFFER_INFO consoleInfo;
    GetConsoleScreenBufferInfo( handle, &consoleInfo );


    WriteToConsole( handle, "0: Default color\n" );
    SetConsoleTextAttribute( handle, FOREGROUND_BLUE | FOREGROUND_INTENSITY | BACKGROUND_RED | BACKGROUND_GREEN );
    WriteToConsole( handle, "1: Blue over brown\n" );
    WriteToConsole( handle, "2: Blue over brown\n" );
    SetConsoleTextAttribute( handle, FOREGROUND_RED | FOREGROUND_INTENSITY | BACKGROUND_BLUE | BACKGROUND_GREEN );
    WriteToConsole( handle, "3: Red over cyan\n" );
    WriteToConsole( handle, "4: Red over cyan\n" );
    WriteToConsole( handle, "5: Red over cyan\n" );

    SetConsoleTextAttribute( handle, consoleInfo.wAttributes );
}

Expected behavior

When a background color is set and then a text shorter than the console width is written followed by a newline, the remaining background color until the right margin should be transparent (showing the underlying console's background - black by default or whatever background color the user has configured), as it happens in cmd consoles; or even filling with the same color that was just set previously from the app could be acceptable.

image

Actual behavior

The wrong behavior described thereafter does not happen all the time, the first time that a new console is opened or after executing the cls command the behavior is right, but after a few executions (less than 10) the wrong behavior begins.

The wrong behavior consists in that after a background color change the next time that a newline is written , the remaining background color until the right margin is filled with the background color that was set previous to the last color change (n-1), and then after this it behaves normally (like cmd, not filled with a solid color).

When the program execution finishes, the background color of the last empty line is drawn with the last color that was set, but this is inconsistent with the behavior of the previous lines (it should be transparent).

image

Originally created by @jgonzalezdr on GitHub (Nov 3, 2020). <!-- 🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨 I ACKNOWLEDGE THE FOLLOWING BEFORE PROCEEDING: 1. If I delete this entire template and go my own path, the core team may close my issue without further explanation or engagement. 2. If I list multiple bugs/concerns in this one issue, the core team may close my issue without further explanation or engagement. 3. If I write an issue that has many duplicates, the core team may close my issue without further explanation or engagement (and without necessarily spending time to find the exact duplicate ID number). 4. If I leave the title incomplete when filing the issue, the core team may close my issue without further explanation or engagement. 5. If I file something completely blank in the body, the core team may close my issue without further explanation or engagement. All good? Then proceed! --> <!-- This bug tracker is monitored by Windows Terminal development team and other technical folks. **Important: When reporting BSODs or security issues, DO NOT attach memory dumps, logs, or traces to Github issues**. Instead, send dumps/traces to secure@microsoft.com, referencing this GitHub issue. If this is an application crash, please also provide a Feedback Hub submission link so we can find your diagnostic data on the backend. Use the category "Apps > Windows Terminal (Preview)" and choose "Share My Feedback" after submission to get the link. Please use this form and describe your issue, concisely but precisely, with as much detail as possible. --> # Environment ```none Windows build number: Microsoft Windows [Versión 10.0.18363.1139] Windows Terminal version (if applicable): 1.3.2651.0 Any other software? ``` # Steps to reproduce Take a program that changes the console background using Win32 API calls like the following, and execute it several times: ``` C #include "windows.h" void WriteToConsole( HANDLE handle, const char* text ) { WriteConsole( handle, text, (DWORD) strlen(text), NULL, NULL ); } void main( int argc, const char* argv[] ) { HANDLE handle = GetStdHandle( STD_OUTPUT_HANDLE ); CONSOLE_SCREEN_BUFFER_INFO consoleInfo; GetConsoleScreenBufferInfo( handle, &consoleInfo ); WriteToConsole( handle, "0: Default color\n" ); SetConsoleTextAttribute( handle, FOREGROUND_BLUE | FOREGROUND_INTENSITY | BACKGROUND_RED | BACKGROUND_GREEN ); WriteToConsole( handle, "1: Blue over brown\n" ); WriteToConsole( handle, "2: Blue over brown\n" ); SetConsoleTextAttribute( handle, FOREGROUND_RED | FOREGROUND_INTENSITY | BACKGROUND_BLUE | BACKGROUND_GREEN ); WriteToConsole( handle, "3: Red over cyan\n" ); WriteToConsole( handle, "4: Red over cyan\n" ); WriteToConsole( handle, "5: Red over cyan\n" ); SetConsoleTextAttribute( handle, consoleInfo.wAttributes ); } ``` # Expected behavior When a background color is set and then a text shorter than the console width is written followed by a newline, the remaining background color until the right margin should be transparent (showing the underlying console's background - black by default or whatever background color the user has configured), as it happens in cmd consoles; or even filling with the same color that was just set previously from the app could be acceptable. ![image](https://user-images.githubusercontent.com/6639296/98006400-7c526d80-1df2-11eb-88ec-9ca1036cc6ca.png) # Actual behavior The wrong behavior described thereafter does not happen all the time, the first time that a new console is opened or after executing the cls command the behavior is right, but after a few executions (less than 10) the wrong behavior begins. The wrong behavior consists in that after a background color change the next time that a newline is written , the remaining background color until the right margin is filled with the background color that was set previous to the last color change (n-1), and then after this it behaves normally (like cmd, not filled with a solid color). When the program execution finishes, the background color of the last empty line is drawn with the last color that was set, but this is inconsistent with the behavior of the previous lines (it should be transparent). ![image](https://user-images.githubusercontent.com/6639296/98006488-99873c00-1df2-11eb-8951-c7a19c01d5ea.png)
claunia commented 2026-01-31 02:42:58 +00:00
Author
Owner
Copy Link

@zadjii-msft commented on GitHub (Nov 3, 2020):

Hmm, so this isn't #3848, because this doesn't have to do with resizing.

This does sound awfully a lot like #7360, which was by design, but that was for attributes written by VT sequences. Since you're using the legacy console APIs here, this probably shouldn't have changed...

Though, I doubt that we'll be able to differentiate between these two cases (writing this test with VT vs Win32 APIs). Even if conhost could differentiate, I'd bet that conpty is gonna blend them into the same VT emitted for the Terminal to use.

@zadjii-msft commented on GitHub (Nov 3, 2020): Hmm, so this _isn't_ #3848, because this doesn't have to do with resizing. This does sound awfully a lot like #7360, which was by design, but that was for attributes written by VT sequences. Since you're using the legacy console APIs here, this probably shouldn't have changed... Though, I doubt that we'll be able to differentiate between these two cases (writing this test with VT vs Win32 APIs). Even if conhost could differentiate, I'd bet that conpty is gonna blend them into the same VT emitted for the Terminal to use.
claunia commented 2026-01-31 02:42:58 +00:00
Author
Owner
Copy Link

@jgonzalezdr commented on GitHub (Nov 3, 2020):

Just in case it may help to track down the bug, I've discovered that if I resize the window, the console is redrawn with a proper behavior, filling with the active background color until the right margin. This behavior after resizing is not the same than cmd, but it is coherent (I assume that this is the intended behavior).

Before resizing:

image

After resizing:

image

@jgonzalezdr commented on GitHub (Nov 3, 2020): Just in case it may help to track down the bug, I've discovered that if I resize the window, the console is redrawn with a proper behavior, filling with the active background color until the right margin. This behavior after resizing is not the same than cmd, but it is coherent (I assume that this is the intended behavior). Before resizing: ![image](https://user-images.githubusercontent.com/6639296/98043993-78404300-1e26-11eb-9bd6-a39a136d2d6d.png) After resizing: ![image](https://user-images.githubusercontent.com/6639296/98044041-8aba7c80-1e26-11eb-9eac-00bbf56fa9bc.png)
claunia commented 2026-01-31 02:42:58 +00:00
Author
Owner
Copy Link

@zadjii-msft commented on GitHub (Aug 23, 2021):

Note to self - this still repros in 1.11, even after #5792.

Though, this does repro at the bottom of conhost's buffer, even without the Terminal. I think this is going to have to be by-design for the Terminal. New lines are going to get initialized with whatever the current attributes are. We could have theoretically scoped a change to "if the console doesn't have VT mode enabled, then don't initialize lines with the current attributes", but even that wouldn't work right here. We enable VT by default for apps running in the Terminal. The app would have to specifically turn VT off. I guess that means this actually was a /dup of #7360

@zadjii-msft commented on GitHub (Aug 23, 2021): Note to self - this still repros in 1.11, even after #5792. Though, this does repro at the _bottom_ of conhost's buffer, even without the Terminal. I think this is going to have to be by-design for the Terminal. New lines are going to get initialized with whatever the current attributes are. We could have theoretically scoped a change to "if the console doesn't have VT mode enabled, then _don't_ initialize lines with the current attributes", but even that wouldn't work right here. We enable VT by default for apps running in the Terminal. The app would have to specifically turn VT _off_. I guess that means this actually was a /dup of #7360
claunia commented 2026-01-31 02:42:58 +00:00
Author
Owner
Copy Link

@ghost commented on GitHub (Aug 23, 2021):

Hi! We've identified this issue as a duplicate of another one that already exists on this Issue Tracker. This specific instance is being closed in favor of tracking the concern over on the referenced thread. Thanks for your report!

@ghost commented on GitHub (Aug 23, 2021): Hi! We've identified this issue as a duplicate of another one that already exists on this Issue Tracker. This specific instance is being closed in favor of tracking the concern over on the referenced thread. Thanks for your report!
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 Area-Output Issue-Bug Priority-2 Product-Terminal Resolution-By-Design 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#11267
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?