CFX_ByteString::Reserve(), ReleaseBuffer() fixes.

core/fxcrt/fx_basic_bstring_unittest.cpp

 // Copyright 2014 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/fxcrt/include/fx_string.h"
 #include "testing/fx_string_testhelpers.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 TEST(fxcrt, ByteStringOperatorSubscript) {
   // CFX_ByteString includes the NUL terminator for non-empty strings.
@@ skipping 606 matching lines @@
     CFX_ByteString fred("FRED");
     CFX_ByteString other_fred = fred;
     const FX_CHAR* old_buffer = fred.c_str();
     fred.TrimLeft();
     EXPECT_EQ("FRED", fred);
     EXPECT_EQ("FRED", other_fred);
     EXPECT_EQ(old_buffer, fred.c_str());
   }
 }
 
+TEST(fxcrt, ByteStringReserve) {
+  {
+    CFX_ByteString str;
+    str.Reserve(6);
+    const FX_CHAR* old_buffer = str.c_str();
+    str += "ABCDEF";
+    EXPECT_EQ(old_buffer, str.c_str());
+    str += "Blah Blah Blah Blah Blah Blah";
+    EXPECT_NE(old_buffer, str.c_str());
+  }
+  {
+    CFX_ByteString str("A");
+    str.Reserve(6);
+    const FX_CHAR* old_buffer = str.c_str();
+    str += "BCDEF";
+    EXPECT_EQ(old_buffer, str.c_str());
+    str += "Blah Blah Blah Blah Blah Blah";
+    EXPECT_NE(old_buffer, str.c_str());
+  }
+}
+
+TEST(fxcrt, ByteStringGetBuffer) {
+  {
+    CFX_ByteString str;
+    FX_CHAR* buffer = str.GetBuffer(12);
+    strcpy(buffer, "clams");
+    str.ReleaseBuffer();
+    EXPECT_EQ("clams", str);
+  }
+  {
+    CFX_ByteString str("cl");
+    FX_CHAR* buffer = str.GetBuffer(12);
+    strcpy(buffer + 2, "ams");
+    str.ReleaseBuffer();
+    EXPECT_EQ("clams", str);
+  }
+}
+
+TEST(fxcrt, ByteStringReleaseBuffer) {
+  {
+    CFX_ByteString str;
+    str.Reserve(12);
+    str += "clams";
+    const FX_CHAR* old_buffer = str.c_str();
+    str.ReleaseBuffer(4);
+    EXPECT_EQ(old_buffer, str.c_str());
+    EXPECT_EQ("clam", str);
+  }
+  {
+    CFX_ByteString str("c");
+    str.Reserve(12);
+    str += "lams";
+    const FX_CHAR* old_buffer = str.c_str();
+    str.ReleaseBuffer(4);
+    EXPECT_EQ(old_buffer, str.c_str());
+    EXPECT_EQ("clam", str);
+  }
+  {
+    CFX_ByteString str;
+    str.Reserve(200);
+    str += "clams";
+    const FX_CHAR* old_buffer = str.c_str();
+    str.ReleaseBuffer(4);
+    EXPECT_NE(old_buffer, str.c_str());
+    EXPECT_EQ("clam", str);
+  }
+  {
+    CFX_ByteString str("c");
+    str.Reserve(200);
+    str += "lams";
+    const FX_CHAR* old_buffer = str.c_str();
+    str.ReleaseBuffer(4);
+    EXPECT_NE(old_buffer, str.c_str());
+    EXPECT_EQ("clam", str);
+  }
+}
+
 TEST(fxcrt, ByteStringCNotNull) {
   CFX_ByteStringC string3("abc");
   CFX_ByteStringC string6("abcdef");
   CFX_ByteStringC alternate_string3("abcdef", 3);
   CFX_ByteStringC embedded_nul_string7("abc\0def", 7);
   CFX_ByteStringC illegal_string7("abcdef", 7);
 
   EXPECT_EQ(3, string3.GetLength());
   EXPECT_EQ(6, string6.GetLength());
   EXPECT_EQ(3, alternate_string3.GetLength());
@@ skipping 352 matching lines @@
   }
 }
 
 TEST(fxcrt, EmptyByteString) {
   CFX_ByteString empty_str;
   EXPECT_TRUE(empty_str.IsEmpty());
   EXPECT_EQ(0, empty_str.GetLength());
   const FX_CHAR* cstr = empty_str.c_str();
   EXPECT_EQ(0, FXSYS_strlen(cstr));
 }