More M3 Wildfire logic; mmap-related bug fixes from Kate

git-svn-id: https://nuttx.svn.sourceforge.net/svnroot/nuttx/trunk@5124 7fd9a85b-ad96-42d3-883c-3090e2eb8679

apps/ChangeLog.txt

@@ -314,3 +314,6 @@
 	  error handling:  Now the number of arguments to mount can be 0 or 4.
 	  Additional parameter checking is required to prevent mysterious errors
 	  (submiteed by Kate).
+	* apps/netutils/webserver/httpd_mmap.c:  Fix errors when the mmap()
+	  length is zero (submitted by Kate).
+

apps/netutils/webserver/httpd_mmap.c

@@ -95,6 +95,15 @@ int httpd_mmap_open(const char *name, struct httpd_fs_file *file)
        return ERROR;
     }
 
+  file->len = (int) st.st_size;
+
+  /* SUS3: "If len is zero, mmap() shall fail and no mapping shall be established." */
+
+  if (st.st_size == 0)
+    {
+      return OK;
+    }
+
   file->fd = open(path, O_RDONLY);
   if (file->fd == -1)
     {
@@ -108,13 +117,16 @@ int httpd_mmap_open(const char *name, struct httpd_fs_file *file)
        return ERROR;
     }
 
-  file->len = (int) st.st_size;
-
   return OK;
 }
 
 int httpd_mmap_close(struct httpd_fs_file *file)
 {
+  if (file->len == 0)
+    {
+      return OK;
+    }
+
 #ifdef CONFIG_FS_RAMMAP
   if (-1 == munmap(file->data, file->len))
     {