sys_link works, including enhanced error handling.

1 files changed, 53 insertions, 7 deletions

diff --git a/src/w32.c b/src/w32.c
index f5938314d16..46f36de8b92 100644
--- a/src/w32.c
+++ b/src/w32.c
@@ -3615,7 +3615,9 @@ sys_link (const char * old, const char * new)
 {
   HANDLE fileh;
   int   result = -1;
-  char oldname[MAX_PATH], newname[MAX_PATH];
+  char oldname[MAX_UTF8_PATH], newname[MAX_UTF8_PATH];
+  wchar_t oldname_w[MAX_PATH];
+  char oldname_a[MAX_PATH];
 
   if (old == NULL || new == NULL)
     {
@@ -3626,8 +3628,18 @@ sys_link (const char * old, const char * new)
   strcpy (oldname, map_w32_filename (old, NULL));
   strcpy (newname, map_w32_filename (new, NULL));
 
-  fileh = CreateFile (oldname, 0, 0, NULL, OPEN_EXISTING,
-                      FILE_FLAG_BACKUP_SEMANTICS, NULL);
+  if (w32_unicode_filenames)
+    {
+      filename_to_utf16 (oldname, oldname_w);
+      fileh = CreateFileW (oldname_w, 0, 0, NULL, OPEN_EXISTING,
+                           FILE_FLAG_BACKUP_SEMANTICS, NULL);
+    }
+  else
+    {
+      filename_to_ansi (oldname, oldname_a);
+      fileh = CreateFileA (oldname_a, 0, 0, NULL, OPEN_EXISTING,
+                           FILE_FLAG_BACKUP_SEMANTICS, NULL);
+    }
   if (fileh != INVALID_HANDLE_VALUE)
     {
       int wlen;
@@ -3644,7 +3656,10 @@ sys_link (const char * old, const char * new)
         WCHAR wbuffer[MAX_PATH];        /* extra space for link name */
       } data;
 
-      wlen = MultiByteToWideChar (CP_ACP, MB_PRECOMPOSED, newname, -1,
+      /* We used to pass MB_PRECOMPOSED as the 2nd arg here, but MSDN
+         indicates that flag is unsupported for CP_UTF8, and OTOH says
+         it is the default anyway.  */
+      wlen = MultiByteToWideChar (CP_UTF8, 0, newname, -1,
                                   data.wid.cStreamName, MAX_PATH);
       if (wlen > 0)
         {
@@ -3668,9 +3683,40 @@ sys_link (const char * old, const char * new)
             }
           else
             {
-              /* Should try mapping GetLastError to errno; for now just
-                 indicate a general error (eg. links not supported).  */
-              errno = EINVAL;  // perhaps EMLINK?
+              DWORD err = GetLastError ();
+              DWORD attributes;
+
+              switch (err)
+                {
+                case ERROR_ACCESS_DENIED:
+                  /* This is what happens when OLDNAME is a directory,
+                     since Windows doesn't support hard links to
+                     directories.  Posix says to set errno to EPERM in
+                     that case.  */
+                  if (w32_unicode_filenames)
+                    attributes = GetFileAttributesW (oldname_w);
+                  else
+                    attributes = GetFileAttributesA (oldname_a);
+                  if (attributes != -1
+                      && (attributes & FILE_ATTRIBUTE_DIRECTORY) != 0)
+                    errno = EPERM;
+                  else if (attributes == -1
+                           && is_unc_volume (oldname)
+                           && unc_volume_file_attributes (oldname) != -1)
+                    errno = EPERM;
+                  else
+                    errno = EACCES;
+                  break;
+                case ERROR_TOO_MANY_LINKS:
+                  errno = EMLINK;
+                  break;
+                case ERROR_NOT_SAME_DEVICE:
+                  errno = EXDEV;
+                  break;
+                default:
+                  errno = EINVAL;
+                  break;
+                }
             }
         }