patch 9.1.0123: MS-Windows: system() may deadlock Commit: https://github.com/vim/vim/commit/52ecc76c7fa1865603f27bc838efaeaa03cad77c Author: GuyBrush <miguel.barro@live.com> Date: Wed Feb 21 20:16:38 2024 +0100 patch 9.1.0123: MS-Windows: system() may deadlock Problem: MS-Windows: system() may deadlock when calling binaries that expect stdin Solution: Ignore the SHELL_EXPAND flag (GuyBrush) This happens on binaries that expect stdin. For example: :echo system("xxd") will cause a deadlock. SHELL_EXPAND is a flag devoted to support the linux implementation of the backtick-expansion mechanism. On linux backtic-expansion relies in the function mch_expand_wildchars() (os_unix.c) that delegates on each specific shell (bash, sh, csh, zsh) the expansion. Basically it composes a shell command that does the expansion and redirects the output to a file and call_shell() it. On windows backtick-expansion is performed by Vim itself. On linux SHELL_EXPAND modifies how mch_call_shell_fork() (os_unix.c) works. This function: - relies on posix fork() to spawn a child process to execute a external command. - Child and parent process communicate using pipes (or pseudoterminal if available). User input (type ahead content) is processed in a loop only if !(SHELL_EXPAND || SHELL_COOKED). Though signals are used to detect Ctrl-C in all cases (the input loop is not necessary to interrupt the function). In the backtick-expansion the external command is the shell command that provides the expansion. For the child redirection: - SHELL_EXPAND replaces stdin, stdout & stderr to /dev/null. This is why the shell command composed includes redirection (otherwise output would be lost). - !SHELL_EXPAND replaces stdin, stdout & stderr with the parent created pipes (or pseudoterminal). Note that the use of SIGINT signal prevents mch_call_shell_fork() from hanging vim. On Windows mch_system_piped() (os_win32.c) (which is only used when the GUI is running) mimics mch_call_shell_fork() (os_unix.c). Win32 lacks fork() and relies on CreateProcessW() and only has pipe support (not pseudoterminal) which makes the implementation much different. But, the key idea is that windows lacks signals, the OS provides support for console apps but gvim is not one. The only way of detecting a Ctrl-C is actually processing user input (type ahead content). By ignoring the user input under SHELL_EXPAND the function can hang gvim. Ignoring SHELL_EXPAND flag has no consequence in Windows because as mentioned above it is only meaningful in linux. closes: #13988 Signed-off-by: GuyBrush <miguel.barro@live.com> Signed-off-by: Christian Brabandt <cb@256bit.org>

" Vim filetype plugin file
" Language:		xhtml
"
" This runtime file is looking for a new maintainer.
"
" Former maintainer:	Dan Sharp
" Last Changed: 	2009 Jan 20
"			2024 Jan 14 by Vim Project (browsefilter)

if exists("b:did_ftplugin") | finish | endif

" Make sure the continuation lines below do not cause problems in
" compatibility mode.
let s:save_cpo = &cpo
set cpo-=C

" Define some defaults in case the included ftplugins don't set them.
let s:undo_ftplugin = ""
let s:browsefilter = "HTML Files (*.html, *.htm)\t*.html;*.htm\n" .
	    \	     "XML Files (*.xml)\t*.xml\n"
if has("win32")
    let s:browsefilter .= "All Files (*.*)\t*\n"
else
    let s:browsefilter .= "All Files (*)\t*\n"
endif
let s:match_words = ""

runtime! ftplugin/xml.vim ftplugin/xml_*.vim ftplugin/xml/*.vim
unlet b:did_ftplugin

" Override our defaults if these were set by an included ftplugin.
if exists("b:undo_ftplugin")
    let s:undo_ftplugin = b:undo_ftplugin
    unlet b:undo_ftplugin
endif
if exists("b:browsefilter")
    let s:browsefilter = b:browsefilter
    unlet b:browsefilter
endif
if exists("b:match_words")
    let s:match_words = b:match_words
    unlet b:match_words
endif

runtime! ftplugin/html.vim ftplugin/html_*.vim ftplugin/html/*.vim
let b:did_ftplugin = 1

" Combine the new set of values with those previously included.
if exists("b:undo_ftplugin")
    let s:undo_ftplugin = b:undo_ftplugin . " | " . s:undo_ftplugin
endif
if exists("b:browsefilter")
    let s:browsefilter = b:browsefilter . s:browsefilter
endif
if exists("b:match_words")
    let s:match_words = b:match_words . "," . s:match_words
endif

" Load the combined list of match_words for matchit.vim
if exists("loaded_matchit")
    let b:match_words = s:match_words
endif

" Change the :browse e filter to primarily show tcsh-related files.
if (has("gui_win32") || has("gui_gtk")) && !exists("b:browsefilter")
    let  b:browsefilter="XHTML files (*.xhtml, *.xhtm)\t*.xhtml;*.xhtm\n" . s:browsefilter
endif

" Undo the stuff we changed.
let b:undo_ftplugin = "unlet! b:browsefilter b:match_words | " . s:undo_ftplugin

" Restore the saved compatibility options.
let &cpo = s:save_cpo
unlet s:save_cpo