From d40bacb83809e3c02ae915774efdd89478ba3102 Mon Sep 17 00:00:00 2001
From: Ray Donnelly <mingw.android@gmail.com>
Date: Mon, 15 Feb 2021 16:22:30 +0100
Subject: [PATCH 1/3] When running Win32 version of luac on mintty or other
 Cygwin/MSYS terminal emulators, Ag cannot detect Cygwin/MSYS pty and it
 causes some problems.

E.g.
https://github.com/ggreer/the_silver_searcher/issues/535#issuecomment-70944218
https://github.com/Alexpux/MSYS2-packages/pull/491

Import a check routine from https://github.com/k-takata/ptycheck .

Copied from a similar patch patch for ag

Credit to: "K.Takata" <kentkt@csc.jp>
---
 src/Makefile   |   2 +-
 src/iscygpty.c | 185 +++++++++++++++++++++++++++++++++++++++++++++++++
 src/iscygpty.h |  41 +++++++++++
 src/lua.c      |   5 ++
 4 files changed, 232 insertions(+), 1 deletion(-)
 create mode 100644 src/iscygpty.c
 create mode 100644 src/iscygpty.h

diff --git a/src/Makefile b/src/Makefile
index a99735a..b495b55 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -33,7 +33,7 @@ CMCFLAGS=
 PLATS= guess aix bsd c89 freebsd generic linux linux-readline macosx mingw posix solaris
 
 LUA_A=	liblua.a
-CORE_O=	lapi.o lcode.o lctype.o ldebug.o ldo.o ldump.o lfunc.o lgc.o llex.o lmem.o lobject.o lopcodes.o lparser.o lstate.o lstring.o ltable.o ltm.o lundump.o lvm.o lzio.o
+CORE_O=	lapi.o lcode.o lctype.o ldebug.o ldo.o ldump.o lfunc.o lgc.o llex.o lmem.o lobject.o lopcodes.o lparser.o lstate.o lstring.o ltable.o ltm.o lundump.o lvm.o lzio.o iscygpty.o
 LIB_O=	lauxlib.o lbaselib.o lcorolib.o ldblib.o liolib.o lmathlib.o loadlib.o loslib.o lstrlib.o ltablib.o lutf8lib.o linit.o
 BASE_O= $(CORE_O) $(LIB_O) $(MYOBJS)
 
diff --git a/src/iscygpty.c b/src/iscygpty.c
new file mode 100644
index 0000000..722f88f
--- /dev/null
+++ b/src/iscygpty.c
@@ -0,0 +1,185 @@
+/*
+ * iscygpty.c -- part of ptycheck
+ * https://github.com/k-takata/ptycheck
+ *
+ * Copyright (c) 2015-2017 K.Takata
+ *
+ * You can redistribute it and/or modify it under the terms of either
+ * the MIT license (as described below) or the Vim license.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#ifdef _WIN32
+
+#include <ctype.h>
+#include <io.h>
+#include <wchar.h>
+#include <windows.h>
+
+#ifdef USE_FILEEXTD
+/* VC 7.1 or earlier doesn't support SAL. */
+# if !defined(_MSC_VER) || (_MSC_VER < 1400)
+#  define __out
+#  define __in
+#  define __in_opt
+# endif
+/* Win32 FileID API Library:
+ * http://www.microsoft.com/en-us/download/details.aspx?id=22599
+ * Needed for WinXP. */
+# include <fileextd.h>
+#else /* USE_FILEEXTD */
+/* VC 8 or earlier. */
+# if defined(_MSC_VER) && (_MSC_VER < 1500)
+#  ifdef ENABLE_STUB_IMPL
+#   define STUB_IMPL
+#  else
+#   error "Win32 FileID API Library is required for VC2005 or earlier."
+#  endif
+# endif
+#endif /* USE_FILEEXTD */
+
+
+#include "iscygpty.h"
+
+//#define USE_DYNFILEID
+#ifdef USE_DYNFILEID
+typedef BOOL (WINAPI *pfnGetFileInformationByHandleEx)(
+		HANDLE                    hFile,
+		FILE_INFO_BY_HANDLE_CLASS FileInformationClass,
+		LPVOID                    lpFileInformation,
+		DWORD                     dwBufferSize
+);
+static pfnGetFileInformationByHandleEx pGetFileInformationByHandleEx = NULL;
+
+# ifndef USE_FILEEXTD
+static BOOL WINAPI stub_GetFileInformationByHandleEx(
+		HANDLE                    hFile,
+		FILE_INFO_BY_HANDLE_CLASS FileInformationClass,
+		LPVOID                    lpFileInformation,
+		DWORD                     dwBufferSize
+		)
+{
+	return FALSE;
+}
+# endif
+
+static void setup_fileid_api(void)
+{
+	if (pGetFileInformationByHandleEx != NULL) {
+		return;
+	}
+	pGetFileInformationByHandleEx = (pfnGetFileInformationByHandleEx)
+		GetProcAddress(GetModuleHandle(TEXT("kernel32.dll")),
+				"GetFileInformationByHandleEx");
+	if (pGetFileInformationByHandleEx == NULL) {
+# ifdef USE_FILEEXTD
+		pGetFileInformationByHandleEx = GetFileInformationByHandleEx;
+# else
+		pGetFileInformationByHandleEx = stub_GetFileInformationByHandleEx;
+# endif
+	}
+}
+#else
+# define pGetFileInformationByHandleEx	GetFileInformationByHandleEx
+# define setup_fileid_api()
+#endif
+
+
+#define is_wprefix(s, prefix) \
+	(wcsncmp((s), (prefix), sizeof(prefix) / sizeof(WCHAR) - 1) == 0)
+
+/* Check if the fd is a cygwin/msys's pty. */
+int is_cygpty(int fd)
+{
+#ifdef STUB_IMPL
+	return 0;
+#else
+	HANDLE h;
+	int size = sizeof(FILE_NAME_INFO) + sizeof(WCHAR) * (MAX_PATH - 1);
+	FILE_NAME_INFO *nameinfo;
+	WCHAR *p = NULL;
+
+	setup_fileid_api();
+
+	h = (HANDLE) _get_osfhandle(fd);
+	if (h == INVALID_HANDLE_VALUE) {
+		return 0;
+	}
+	/* Cygwin/msys's pty is a pipe. */
+	if (GetFileType(h) != FILE_TYPE_PIPE) {
+		return 0;
+	}
+	nameinfo = malloc(size + sizeof(WCHAR));
+	if (nameinfo == NULL) {
+		return 0;
+	}
+	/* Check the name of the pipe:
+	 * '\{cygwin,msys}-XXXXXXXXXXXXXXXX-ptyN-{from,to}-master' */
+	if (pGetFileInformationByHandleEx(h, FileNameInfo, nameinfo, size)) {
+		nameinfo->FileName[nameinfo->FileNameLength / sizeof(WCHAR)] = L'\0';
+		p = nameinfo->FileName;
+		if (is_wprefix(p, L"\\cygwin-")) {		/* Cygwin */
+			p += 8;
+		} else if (is_wprefix(p, L"\\msys-")) {	/* MSYS and MSYS2 */
+			p += 6;
+		} else {
+			p = NULL;
+		}
+		if (p != NULL) {
+			while (*p && isxdigit(*p))	/* Skip 16-digit hexadecimal. */
+				++p;
+			if (is_wprefix(p, L"-pty")) {
+				p += 4;
+			} else {
+				p = NULL;
+			}
+		}
+		if (p != NULL) {
+			while (*p && isdigit(*p))	/* Skip pty number. */
+				++p;
+			if (is_wprefix(p, L"-from-master")) {
+				//p += 12;
+			} else if (is_wprefix(p, L"-to-master")) {
+				//p += 10;
+			} else {
+				p = NULL;
+			}
+		}
+	}
+	free(nameinfo);
+	return (p != NULL);
+#endif /* STUB_IMPL */
+}
+
+/* Check if at least one cygwin/msys pty is used. */
+int is_cygpty_used(void)
+{
+	int fd, ret = 0;
+
+	for (fd = 0; fd < 3; fd++) {
+		ret |= is_cygpty(fd);
+	}
+	return ret;
+}
+
+#endif /* _WIN32 */
+
+/* vim: set ts=4 sw=4: */
diff --git a/src/iscygpty.h b/src/iscygpty.h
new file mode 100644
index 0000000..82fd0af
--- /dev/null
+++ b/src/iscygpty.h
@@ -0,0 +1,41 @@
+/*
+ * iscygpty.h -- part of ptycheck
+ * https://github.com/k-takata/ptycheck
+ *
+ * Copyright (c) 2015-2017 K.Takata
+ *
+ * You can redistribute it and/or modify it under the terms of either
+ * the MIT license (as described below) or the Vim license.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#ifndef _ISCYGPTY_H
+#define _ISCYGPTY_H
+
+#ifdef _WIN32
+int is_cygpty(int fd);
+int is_cygpty_used(void);
+#else
+#define is_cygpty(fd)		0
+#define is_cygpty_used()	0
+#endif
+
+#endif /* _ISCYGPTY_H */
diff --git a/src/lua.c b/src/lua.c
index b5b884b..3eb2c33 100644
--- a/src/lua.c
+++ b/src/lua.c
@@ -20,6 +20,7 @@
 #include "lauxlib.h"
 #include "lualib.h"
 
+#include "iscygpty.h"
 
 #if !defined(LUA_PROGNAME)
 #define LUA_PROGNAME		"lua"
@@ -365,7 +366,11 @@ static int handle_luainit (lua_State *L) {
 #if defined(LUA_USE_POSIX)	/* { */
 
 #include <unistd.h>
+#ifdef _WIN32
+#define lua_stdin_is_tty()	iscygpty(0)
+#else
 #define lua_stdin_is_tty()	isatty(0)
+#endif
 
 #elif defined(LUA_USE_WINDOWS)	/* }{ */
 
-- 
2.30.0.windows.2