From ba1806251ff8ff695175b92ab5732eadbcd2f72e Mon Sep 17 00:00:00 2001
From: Qiu Shumin <shumin.qiu@intel.com>
Date: Mon, 24 Aug 2015 07:42:27 +0000
Subject: MdePkg/Library/UefiFileHandleLib: Make FileHandleReadLine return the
 right buffer size.

1. '\r' char will not return in buffer so buffer size should exclude the number of '\r' char.
2. When 'Truncate' is TRUE return the truncated string with 'EFI_SUCCESS' status.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Qiu Shumin <shumin.qiu@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@18276 6f19259b-4bc3-4df7-8a09-765794883524
---
 MdePkg/Include/Library/FileHandleLib.h             |  2 ++
 .../Library/UefiFileHandleLib/UefiFileHandleLib.c  | 34 +++++++++++++++-------
 2 files changed, 25 insertions(+), 11 deletions(-)

(limited to 'MdePkg')

diff --git a/MdePkg/Include/Library/FileHandleLib.h b/MdePkg/Include/Library/FileHandleLib.h
index b5ac19a..fdbdc3a 100644
--- a/MdePkg/Include/Library/FileHandleLib.h
+++ b/MdePkg/Include/Library/FileHandleLib.h
@@ -379,6 +379,8 @@ FileHandleGetFileName (
 
   If the position upon start is 0, then the Ascii Boolean will be set.  This should be
   maintained and not changed for all operations with the same file.
+  The function will not return the \r and \n character in buffer. When an empty line is
+  read a CHAR_NULL character will be returned in buffer.
 
   @param[in]       Handle        FileHandle to read from.
   @param[in, out]  Buffer        The pointer to buffer to read into.
diff --git a/MdePkg/Library/UefiFileHandleLib/UefiFileHandleLib.c b/MdePkg/Library/UefiFileHandleLib/UefiFileHandleLib.c
index f6cbfad..a31d12b 100644
--- a/MdePkg/Library/UefiFileHandleLib/UefiFileHandleLib.c
+++ b/MdePkg/Library/UefiFileHandleLib/UefiFileHandleLib.c
@@ -913,6 +913,8 @@ FileHandleReturnLine(
 
   If the position upon start is 0, then the Ascii Boolean will be set.  This should be
   maintained and not changed for all operations with the same file.
+  The function will not return the \r and \n character in buffer. When an empty line is
+  read a CHAR_NULL character will be returned in buffer.
 
   @param[in]       Handle        FileHandle to read from.
   @param[in, out]  Buffer        The pointer to buffer to read into.
@@ -949,6 +951,7 @@ FileHandleReadLine(
   UINT64      FileSize;
   UINTN       CharSize;
   UINTN       CountSoFar;
+  UINTN       CrCount;
   UINT64      OriginalFilePosition;
 
   if (Handle == NULL
@@ -958,14 +961,15 @@ FileHandleReadLine(
     return (EFI_INVALID_PARAMETER);
   } 
   
-  if (Buffer != NULL) {
+  if (Buffer != NULL && *Size != 0) {
     *Buffer = CHAR_NULL;
-  }
+  } 
   
   Status = FileHandleGetSize (Handle, &FileSize);
   if (EFI_ERROR (Status)) {
     return Status;
   } else if (FileSize == 0) {
+    *Ascii = TRUE;
     return EFI_SUCCESS;
   }  
   
@@ -982,6 +986,7 @@ FileHandleReadLine(
     }
   }
 
+  CrCount = 0;
   for (CountSoFar = 0;;CountSoFar++){
     CharBuffer = 0;
     if (*Ascii) {
@@ -996,31 +1001,38 @@ FileHandleReadLine(
        || (CharBuffer ==  '\n' && *Ascii)
      ){
       break;
+    } else if (
+        (CharBuffer == L'\r' && !(*Ascii)) ||
+        (CharBuffer ==  '\r' && *Ascii)
+      ) {
+      CrCount++;
+      continue;
     }
     //
     // if we have space save it...
     //
-    if ((CountSoFar+1)*sizeof(CHAR16) < *Size){
+    if ((CountSoFar+1-CrCount)*sizeof(CHAR16) < *Size){
       ASSERT(Buffer != NULL);
-      ((CHAR16*)Buffer)[CountSoFar] = CharBuffer;
-      ((CHAR16*)Buffer)[CountSoFar+1] = CHAR_NULL;
+      ((CHAR16*)Buffer)[CountSoFar-CrCount] = CharBuffer;
+      ((CHAR16*)Buffer)[CountSoFar+1-CrCount] = CHAR_NULL;
     }
   }
 
   //
   // if we ran out of space tell when...
   //
-  if ((CountSoFar+1)*sizeof(CHAR16) > *Size){
-    *Size = (CountSoFar+1)*sizeof(CHAR16);
+  if ((CountSoFar+1-CrCount)*sizeof(CHAR16) > *Size){
+    *Size = (CountSoFar+1-CrCount)*sizeof(CHAR16);
     if (!Truncate) {
+      if (Buffer != NULL && *Size != 0) {
+        ZeroMem(Buffer, *Size);
+      }
       FileHandleSetPosition(Handle, OriginalFilePosition);
+      return (EFI_BUFFER_TOO_SMALL);
     } else {
       DEBUG((DEBUG_WARN, "The line was truncated in FileHandleReadLine"));
+      return (EFI_SUCCESS);
     }
-    return (EFI_BUFFER_TOO_SMALL);
-  }
-  while(Buffer[StrLen(Buffer)-1] == L'\r') {
-    Buffer[StrLen(Buffer)-1] = CHAR_NULL;
   }
 
   return (Status);
-- 
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