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Preserve saved console modes with redirected stdio - #382
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With console stdin but captured stdout and stderr, a runtime child can replace the shared saved output mode with zero. A later invocation restores that value, rendering CR/LF as glyphs instead of line breaks. Redirected stdin with console output exposes the corresponding input-mode omission. Console handlers restore both modes on close, even with redirected stdio. Keep their backups valid regardless of whether opening the handler needs to switch either mode. Addresses: #379 Fixes: bbd3710 ("Cygwin: console: Set console mode only if std{in,out,err} is console") Assisted-by: GPT-6.1 Signed-off-by: Johannes Schindelin <[email protected]> (cherry picked from commit 717d7aac57eddbfc2ddb011b249ffe8d87148729)
When stdout and stderr are redirected but stdin remains attached to the console, starting a Cygwin child via a native launcher must not clear ENABLE_PROCESSED_OUTPUT. Protect the behavior restored by 717d7aac57 (Cygwin: console: Preserve saved modes with redirected stdio) against future regressions. Addresses: #379 Assisted-by: GPT-6.1 Signed-off-by: Johannes Schindelin <[email protected]> (cherry picked from commit bff49354caeae98b20fa7ca307bfe6e2649ff490)
dscho
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The PR builds currently fail because staging already published mingw-w64-ucrt-x86_64-llvm-libs 23.1.3-1 (upgraded from 22.1.8-3), which provides libLLVM-23.dll and removes libLLVM-22.dll. That's why EDIT: once |
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) msys2/msys2-runtime#379 reports that executing an MSYS2 process with redirected standard streams (such as invoking `pacman` via Python's `subprocess.run(..., capture_output=True)`) causes the Windows console output mode to drop from `0x7` to `0x0`. This clears `ENABLE_PROCESSED_OUTPUT`, `ENABLE_WRAP_AT_EOL_OUTPUT`, and `ENABLE_VIRTUAL_TERMINAL_PROCESSING`, leaving the hosting console unable to interpret carriage returns, line feeds, and ANSI escape sequences properly. The root cause lies in the console mode saving and restoration logic: when standard I/O handles are redirected away from the console (for example, into pipes), `fhandler_console::open()` skipped populating the process-local `prev_output_mode_backup` (or `prev_input_mode_backup`), leaving them zero. When the process later exits and console mode restoration runs in `close()`, that zero backup value is moved into the shared `con.prev_output_mode`, which the subsequent invocation restores to the Windows console handle, stripping the active mode flags. To resolve this, we ensure the process-local backup modes are initialized from `con.prev_output_mode` and `con.prev_input_mode` unconditionally in `fhandler_console::open()` under `cons_mode_mutex` before checking whether standard handles are consoles. A companion test case in the testsuite exercises running commands under redirected stdio to verify that the console mode remains intact across executions. This addresses msys2/msys2-runtime#379 This corresponds to msys2/msys2-runtime#382
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…tdio (#6788) msys2/msys2-runtime#379 reports that executing an MSYS2 process with redirected standard streams (such as invoking `pacman` via Python's `subprocess.run(..., capture_output=True)`) causes the Windows console output mode to drop from `0x7` to `0x0`. This clears `ENABLE_PROCESSED_OUTPUT`, `ENABLE_WRAP_AT_EOL_OUTPUT`, and `ENABLE_VIRTUAL_TERMINAL_PROCESSING`, leaving the hosting console unable to interpret carriage returns, line feeds, and ANSI escape sequences properly. The root cause lies in the console mode saving and restoration logic: when standard I/O handles are redirected away from the console (for example, into pipes), `fhandler_console::open()` skipped populating the process-local `prev_output_mode_backup` (or `prev_input_mode_backup`), leaving them zero. When the process later exits and console mode restoration runs in `close()`, that zero backup value is moved into the shared `con.prev_output_mode`, which the subsequent invocation restores to the Windows console handle, stripping the active mode flags. To resolve this, we ensure the process-local backup modes are initialized from `con.prev_output_mode` and `con.prev_input_mode` unconditionally in `fhandler_console::open()` under `cons_mode_mutex` before checking whether standard handles are consoles. A companion test case in the testsuite exercises running commands under redirected stdio to verify that the console mode remains intact across executions. This addresses msys2/msys2-runtime#379 This corresponds to msys2/msys2-runtime#382 Source: msys2/MSYS2-packages@c98a0dd
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#379 reports that executing an MSYS2 process with redirected standard streams (such as invoking
pacmanvia Python'ssubprocess.run(..., capture_output=True)) causes the Windows console output mode to drop from0x7to0x0. This clearsENABLE_PROCESSED_OUTPUT,ENABLE_WRAP_AT_EOL_OUTPUT, andENABLE_VIRTUAL_TERMINAL_PROCESSING, leaving the hosting console unable to interpret carriage returns, line feeds, and ANSI escape sequences properly.The root cause lies in the console mode saving and restoration logic: when standard I/O handles are redirected away from the console (for example, into pipes),
fhandler_console::open()skipped populating the process-localprev_output_mode_backup(orprev_input_mode_backup), leaving them zero. When the process later exits and console mode restoration runs inclose(), that zero backup value is moved into the sharedcon.prev_output_mode, which the subsequent invocation restores to the Windows console handle, stripping the active mode flags.To resolve this, we ensure the process-local backup modes are initialized from
con.prev_output_modeandcon.prev_input_modeunconditionally infhandler_console::open()undercons_mode_mutexbefore checking whether standard handles are consoles. A companion test case in the testsuite exercises running commands under redirected stdio to verify that the console mode remains intact across executions.This addresses #379