MdePkg BaseLib: API PathRemoveLastItem not handle root paths properly

https://bugzilla.tianocore.org/show_bug.cgi?id=239

When the input path for API PathRemoveLastItem() is a root path like
'fs0:\', the API will return TRUE (indicating a directory or file was
removed from the path) and modifies the path to 'fs0:'. In fact, there's
no directory or file removed in the above case.

This commit adds additional check to resolve this issue and modifies the
API's description to make it more straightforward.

Cc: Ruiyu Ni <ruiyu.ni@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Hao Wu <hao.a.wu@intel.com>
Reviewed-by: Ruiyu Ni <ruiyu.ni@intel.com>

1 files changed, 5 insertions, 4 deletions

diff --git a/MdePkg/Library/BaseLib/FilePaths.c b/MdePkg/Library/BaseLib/FilePaths.c
index 183b3234d3..29a84ea902 100644
--- a/MdePkg/Library/BaseLib/FilePaths.c
+++ b/MdePkg/Library/BaseLib/FilePaths.c
@@ -14,9 +14,8 @@
 #include  <Library/BaseLib.h>

 

 /**

-  Removes the last directory or file entry in a path by changing the last

-  L'\' to a CHAR_NULL. For a path which is like L"fs0:startup.nsh",

-  it's converted to L"fs0:".

+  Removes the last directory or file entry in a path. For a path which is

+  like L"fs0:startup.nsh", it's converted to L"fs0:".

 

   @param[in,out] Path     A pointer to the path to modify.

 

@@ -38,7 +37,9 @@ PathRemoveLastItem(
       ; Walker != NULL && *Walker != CHAR_NULL

       ; Walker++

      ){

-    if ((*Walker == L'\\' || *Walker == L':') && *(Walker + 1) != CHAR_NULL) {

+    if (*Walker == L'\\' && *(Walker + 1) != CHAR_NULL) {

+      LastSlash = Walker+1;

+    } else if (*Walker == L':' && *(Walker + 1) != L'\\' && *(Walker + 1) != CHAR_NULL) {

       LastSlash = Walker+1;

     }

   }