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>

/* vi:set ts=8 sts=4 sw=4 noet:
 *
 * VIM - Vi IMproved		by Bram Moolenaar
 *
 * Do ":help uganda"  in Vim to read copying and usage conditions.
 * Do ":help credits" in Vim to see a list of people who contributed.
 */

/*
 * Define the version number, name, etc.
 * The patchlevel is in included_patches[], in version.c.
 */

// Trick to turn a number into a string.
#define VIM_TOSTR_(a)			#a
#define VIM_TOSTR(a)			VIM_TOSTR_(a)

// Values that change for a new release.
#define VIM_VERSION_MAJOR		9
#define VIM_VERSION_MINOR		1
#define VIM_VERSION_BUILD		285
#define VIM_VERSION_BUILD_BCD		0x11d
#define VIM_VERSION_DATE_ONLY		"2024 Jan 02"

// Values based on the above
#define VIM_VERSION_MAJOR_STR		VIM_TOSTR(VIM_VERSION_MAJOR)
#define VIM_VERSION_MINOR_STR		VIM_TOSTR(VIM_VERSION_MINOR)
#define VIM_VERSION_100	    (VIM_VERSION_MAJOR * 100 + VIM_VERSION_MINOR)

#define VIM_VERSION_BUILD_STR		VIM_TOSTR(VIM_VERSION_BUILD)
#ifndef VIM_VERSION_PATCHLEVEL
# define VIM_VERSION_PATCHLEVEL		0
#endif
#define VIM_VERSION_PATCHLEVEL_STR	VIM_TOSTR(VIM_VERSION_PATCHLEVEL)
// Used by MacOS port; should be one of: development, alpha, beta, final
#define VIM_VERSION_RELEASE		final

/*
 * VIM_VERSION_NODOT is used for the runtime directory name.
 * VIM_VERSION_SHORT is copied into the swap file (max. length is 6 chars).
 * VIM_VERSION_MEDIUM is used for the startup-screen.
 * VIM_VERSION_LONG is used for the ":version" command and "Vim -h".
 */
#define VIM_VERSION_NODOT     "vim" VIM_VERSION_MAJOR_STR VIM_VERSION_MINOR_STR
#define VIM_VERSION_SHORT     VIM_VERSION_MAJOR_STR "." VIM_VERSION_MINOR_STR
#define VIM_VERSION_MEDIUM    VIM_VERSION_SHORT
#define VIM_VERSION_LONG_ONLY "VIM - Vi IMproved " VIM_VERSION_MEDIUM
#define VIM_VERSION_LONG_HEAD VIM_VERSION_LONG_ONLY " (" VIM_VERSION_DATE_ONLY
#define VIM_VERSION_LONG      VIM_VERSION_LONG_HEAD ")"
#define VIM_VERSION_LONG_DATE VIM_VERSION_LONG_HEAD ", compiled "