[dos] Do not define CONFIG_OS_UNIX for DOS

configure.ac

@@ -189,6 +189,7 @@ test "$CONFIG_OS_OS2" = yes && LDFLAGS=`echo "$LDFLAGS" | sed "s/-Zexe//g"`
 AC_MSG_CHECKING([for UNIX])
 dnl FIXME: some depend kind of mechanism
 if test "$CONFIG_OS_BEOS" = no && \
+   test "$CONFIG_OS_DOS" = no && \
    test "$CONFIG_OS_RISCOS" = no && \
    test "$CONFIG_OS_WIN32" = no && \
    test "$CONFIG_OS_OS2" = no; then

src/osdep/dos/dos.c

@@ -80,6 +80,18 @@ do {                                                                    \
 
 #define overalloc()     overalloc_at(__FILE__, __LINE__)
 
+int
+is_xterm(void)
+{
+	return 0;
+}
+
+int
+get_system_env(void)
+{
+	return (0);
+}
+
 int
 set_nonblocking_fd(int fd)
 {

src/osdep/dos/sysinfo.h

@@ -0,0 +1,19 @@
+
+#ifndef EL__OSDEP_DOS_SYSINFO_H
+#define EL__OSDEP_DOS_SYSINFO_H
+
+#ifdef CONFIG_OS_DOS
+
+#define SYSTEM_NAME	"DOS"
+#define SYSTEM_STR	"DOS"
+#define DEFAULT_SHELL	"command.com"
+#define GETSHELL	getenv("COMSPEC")
+
+#define dir_sep(x) ((x) == '/' || (x) == '\\')
+#define NO_ASYNC_LOOKUP
+/* #define NO_FG_EXEC */
+#define DOS_FS
+#define NO_FORK_ON_EXIT
+
+#endif
+#endif

src/osdep/system.h

@@ -2,6 +2,7 @@
 #define EL__OSDEP_SYSTEM_H
 
 #if !defined(CONFIG_OS_BEOS) \
+     && !defined(CONFIG_OS_DOS) \
      && !defined(CONFIG_OS_OS2) \
      && !defined(CONFIG_OS_RISCOS) \
      && !defined(CONFIG_OS_UNIX) \
@@ -15,6 +16,7 @@
 #include "osdep/win32/overrides.h"
 
 #include "osdep/beos/sysinfo.h"
+#include "osdep/dos/sysinfo.h"
 #include "osdep/os2/sysinfo.h"
 #include "osdep/riscos/sysinfo.h"
 #include "osdep/unix/sysinfo.h"

src/protocol/uri.c

@@ -602,7 +602,7 @@ add_uri_to_string(struct string *string, const struct uri *uri,
 			"URI_FILENAME should be used alone %d", components);
 
 		if (wants(URI_PATH) && !is_uri_dir_sep(uri, *filename)) {
-#ifdef CONFIG_OS_WIN32
+#if defined(CONFIG_OS_WIN32) || defined(CONFIG_OS_DOS)
 			if (uri->protocol != PROTOCOL_FILE)
 #endif
 			/* FIXME: Add correct separator */