Fix putenv and unsetenv on MS-Windows.

[gnu-emacs] / src / w32.c

diff --git a/src/w32.c b/src/w32.c
index da778eb85415ff37114fb89065cdf3fce99c05b7..b6bb653369d5230b56a35d1ef0debbd05e8d46f2 100644 (file)
--- a/src/w32.c
+++ b/src/w32.c
@@ -150,10 +150,18 @@ typedef struct _REPARSE_DATA_BUFFER {
     } DUMMYUNIONNAME;
 } REPARSE_DATA_BUFFER, *PREPARSE_DATA_BUFFER;
 
+#ifndef FILE_DEVICE_FILE_SYSTEM
 #define FILE_DEVICE_FILE_SYSTEM        9
+#endif
+#ifndef METHOD_BUFFERED
 #define METHOD_BUFFERED                0
+#endif
+#ifndef FILE_ANY_ACCESS
 #define FILE_ANY_ACCESS                0x00000000
+#endif
+#ifndef CTL_CODE
 #define CTL_CODE(t,f,m,a)       (((t)<<16)|((a)<<14)|((f)<<2)|(m))
+#endif
 #define FSCTL_GET_REPARSE_POINT \
   CTL_CODE(FILE_DEVICE_FILE_SYSTEM, 42, METHOD_BUFFERED, FILE_ANY_ACCESS)
 #endif
@@ -179,7 +187,7 @@ typedef struct _REPARSE_DATA_BUFFER {
 #undef sendto
 
 #include "w32.h"
-#include "ndir.h"
+#include <dirent.h>
 #include "w32common.h"
 #include "w32heap.h"
 #include "w32select.h"
@@ -908,7 +916,7 @@ static char startup_dir[MAXPATHLEN];
 
 /* Get the current working directory.  */
 char *
-getcwd (char *dir, size_t dirsize)
+getcwd (char *dir, int dirsize)
 {
   if (!dirsize)
     {
@@ -1536,6 +1544,50 @@ is_unc_volume (const char *filename)
   return 1;
 }
 
+/* Emulate the Posix unsetenv.  */
+int
+unsetenv (const char *name)
+{
+  char *var;
+  size_t name_len;
+  int retval;
+
+  if (name == NULL || *name == '\0' || strchr (name, '=') != NULL)
+    {
+      errno = EINVAL;
+      return -1;
+    }
+  name_len = strlen (name);
+  /* MS docs says an environment variable cannot be longer than 32K.  */
+  if (name_len > 32767)
+    {
+      errno = ENOMEM;
+      return 0;
+    }
+  /* It is safe to use 'alloca' with 32K size, since the stack is at
+     least 2MB, and we set it to 8MB in the link command line.  */
+  var = alloca (name_len + 2);
+  var[name_len++] = '=';
+  var[name_len] = '\0';
+  return _putenv (var);
+}
+
+/* MS _putenv doesn't support removing a variable when the argument
+   does not include the '=' character, so we fix that here.  */
+int
+sys_putenv (char *str)
+{
+  const char *const name_end = strchr (str, '=');
+
+  if (name_end == NULL)
+    {
+      /* Remove the variable from the environment.  */
+      return unsetenv (str);
+    }
+
+  return _putenv (str);
+}
+
 #define REG_ROOT "SOFTWARE\\GNU\\Emacs"
 
 LPBYTE
@@ -2448,7 +2500,7 @@ is_exec (const char * name)
    and readdir.  We can't use the procedures supplied in sysdep.c,
    so we provide them here.  */
 
-struct direct dir_static;       /* simulated directory contents */
+struct dirent dir_static;       /* simulated directory contents */
 static HANDLE dir_find_handle = INVALID_HANDLE_VALUE;
 static int    dir_is_fat;
 static char   dir_pathname[MAXPATHLEN+1];
@@ -2518,7 +2570,7 @@ closedir (DIR *dirp)
   xfree ((char *) dirp);
 }
 
-struct direct *
+struct dirent *
 readdir (DIR *dirp)
 {
   int downcase = !NILP (Vw32_downcase_file_names);
@@ -2572,7 +2624,7 @@ readdir (DIR *dirp)
       downcase = 1;    /* 8+3 aliases are returned in all caps */
     }
   dir_static.d_namlen = strlen (dir_static.d_name);
-  dir_static.d_reclen = sizeof (struct direct) - MAXNAMLEN + 3 +
+  dir_static.d_reclen = sizeof (struct dirent) - MAXNAMLEN + 3 +
     dir_static.d_namlen - dir_static.d_namlen % 4;
 
   /* If the file name in cFileName[] includes `?' characters, it means