From 62e71e2fbeaaf76e1faa43ccc7a945c44463589e Mon Sep 17 00:00:00 2001
From: rsun3 <rsun3@6f19259b-4bc3-4df7-8a09-765794883524>
Date: Fri, 8 May 2009 05:22:17 +0000
Subject: [PATCH] Fix bugs in StrStr() and AsciiStrStr().

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@8261 6f19259b-4bc3-4df7-8a09-765794883524
---
 MdePkg/Library/BaseLib/String.c | 37 ++++++++++++++++-----------------
 1 file changed, 18 insertions(+), 19 deletions(-)

diff --git a/MdePkg/Library/BaseLib/String.c b/MdePkg/Library/BaseLib/String.c
index 6717308473..50253de04f 100644
--- a/MdePkg/Library/BaseLib/String.c
+++ b/MdePkg/Library/BaseLib/String.c
@@ -478,29 +478,29 @@ StrStr (
   ASSERT (StrSize (String) != 0);
   ASSERT (StrSize (SearchString) != 0);
 
-  while (*String != '\0') {
+  if (*SearchString == L'\0') {
+    return NULL;
+  }
+
+  while (*String != L'\0') {
     SearchStringTmp = SearchString;
     FirstMatch = String;
     
     while ((*String == *SearchStringTmp) 
-            && (*SearchStringTmp != '\0') 
-            && (*String != '\0')) {
+            && (*String != L'\0')) {
       String++;
       SearchStringTmp++;
     } 
     
-    if (*SearchStringTmp == '\0') {
+    if (*SearchStringTmp == L'\0') {
       return (CHAR16 *) FirstMatch;
     }
 
-    if (SearchStringTmp == SearchString) {
-      //
-      // If no character from SearchString match,
-      // move the pointer to the String under search
-      // by one character.
-      //
-      String++;
+    if (*String == L'\0') {
+      return NULL;
     }
+
+    String = FirstMatch + 1;
   }
 
   return NULL;
@@ -1616,12 +1616,15 @@ AsciiStrStr (
   ASSERT (AsciiStrSize (String) != 0);
   ASSERT (AsciiStrSize (SearchString) != 0);
 
+  if (*SearchString == '\0') {
+    return NULL;
+  }
+
   while (*String != '\0') {
     SearchStringTmp = SearchString;
     FirstMatch = String;
     
     while ((*String == *SearchStringTmp) 
-            && (*SearchStringTmp != '\0') 
             && (*String != '\0')) {
       String++;
       SearchStringTmp++;
@@ -1631,15 +1634,11 @@ AsciiStrStr (
       return (CHAR8 *) FirstMatch;
     }
 
-    if (SearchStringTmp == SearchString) {
-      //
-      // If no character from SearchString match,
-      // move the pointer to the String under search
-      // by one character.
-      //
-      String++;
+    if (*String == '\0') {
+      return NULL;
     }
 
+    String = FirstMatch + 1;
   }
 
   return NULL;
-- 
2.39.2