Fix GHSA-p99j-rfp4-xqvq

It's no use trying to work around whatever the operating system and Apache
do because we'll be fighting that until eternity.
Change the skip_getopt condition such that when we're running in
CGI or FastCGI mode we always skip the argument parsing.
This is a BC break, but this seems to be the only way to get rid of this
class of issues.

Author: nielsdos

sapi/cgi/cgi_main.c

@@ -1748,7 +1748,6 @@ int main(int argc, char *argv[])
 	int status = 0;
 #endif
 	char *query_string;
-	char *decoded_query_string;
 	int skip_getopt = 0;
 
 #if defined(SIGPIPE) && defined(SIG_IGN)
@@ -1803,10 +1802,15 @@ int main(int argc, char *argv[])
 	 * the executable. Ideally we skip argument parsing when we're in cgi or fastcgi mode,
 	 * but that breaks PHP scripts on Linux with a hashbang: `#!/php-cgi -d option=value`.
 	 * Therefore, this code only prevents passing arguments if the query string starts with a '-'.
-	 * Similarly, scripts spawned in subprocesses on Windows may have the same issue. */
+	 * Similarly, scripts spawned in subprocesses on Windows may have the same issue.
+	 * However, Windows has lots of conversion rules and command line parsing rules that
+	 * are too difficult and dangerous to reliably emulate. */
 	if((query_string = getenv("QUERY_STRING")) != NULL && strchr(query_string, '=') == NULL) {
+#ifdef PHP_WIN32
+		skip_getopt = cgi || fastcgi;
+#else
 		unsigned char *p;
-		decoded_query_string = strdup(query_string);
+		char *decoded_query_string = strdup(query_string);
 		php_url_decode(decoded_query_string, strlen(decoded_query_string));
 		for (p = (unsigned char *)decoded_query_string; *p &&  *p <= ' '; p++) {
 			/* skip all leading spaces */
@@ -1815,22 +1819,8 @@ int main(int argc, char *argv[])
 			skip_getopt = 1;
 		}
 
-		/* On Windows we have to take into account the "best fit" mapping behaviour. */
-#ifdef PHP_WIN32
-		if (*p >= 0x80) {
-			wchar_t wide_buf[1];
-			wide_buf[0] = *p;
-			char char_buf[4];
-			size_t wide_buf_len = sizeof(wide_buf) / sizeof(wide_buf[0]);
-			size_t char_buf_len = sizeof(char_buf) / sizeof(char_buf[0]);
-			if (WideCharToMultiByte(CP_ACP, 0, wide_buf, wide_buf_len, char_buf, char_buf_len, NULL, NULL) == 0
-				|| char_buf[0] == '-') {
-				skip_getopt = 1;
-			}
-		}
-#endif
-
 		free(decoded_query_string);
+#endif
 	}
 
 	while (!skip_getopt && (c = php_getopt(argc, argv, OPTIONS, &php_optarg, &php_optind, 0, 2)) != -1) {