Fix exponential growing of string buffer in Append() helper function.

diff --git a/Src/Common/UniFile.cpp b/Src/Common/UniFile.cpp
index 6c56e2c..ae13212 100644 (file)
--- a/Src/Common/UniFile.cpp
+++ b/Src/Common/UniFile.cpp
@@ -44,7 +44,7 @@ THE SOFTWARE.
 static char THIS_FILE[] = __FILE__;
 #endif
 
-static int Append(String &strBuffer, int cchHead, LPCTSTR pchTail, int cchTail,
+static void Append(String &strBuffer, LPCTSTR pchTail, int cchTail,
                int cchBufferMin = 1024);
 
 /**
@@ -69,9 +69,9 @@ bool UniFile::UniError::HasError() const
  */
 void UniFile::UniError::ClearError()
 {
-       apiname.clear();
+       apiname.erase();
        syserrnum = ERROR_SUCCESS;
-       desc.clear();
+       desc.erase();
 }
 
 /**
@@ -103,8 +103,8 @@ void UniLocalFile::Clear()
 {
        m_statusFetched = 0;
        m_filesize = 0;
-       m_filepath.clear();
-       m_filename.clear();
+       m_filepath.erase();
+       m_filename.erase();
        m_lineno = -1;
        m_unicoding = ucr::NONE;
        m_charsize = 1;
@@ -423,22 +423,22 @@ BOOL UniMemFile::ReadString(String & line, bool * lossy)
  * @param [in] cchBufferMin Minimum size for the buffer.
  * @return New length of the string.
  */
-static int Append(String &strBuffer, int cchHead, LPCTSTR pchTail,
+static void Append(String &strBuffer, LPCTSTR pchTail,
                int cchTail, int cchBufferMin)
 {
-       int cchBuffer = strBuffer.length();
+       int cchBuffer = strBuffer.capacity();
+       int cchHead = strBuffer.length();
        int cchLength = cchHead + cchTail;
        while (cchBuffer < cchLength)
        {
+               ASSERT((cchBufferMin & cchBufferMin - 1) == 0); // must be a power of 2
+               cchBuffer &= ~(cchBufferMin - 1); // truncate to a multiple of cchBufferMin
                cchBuffer += cchBuffer;
                if (cchBuffer < cchBufferMin)
                        cchBuffer = cchBufferMin;
        }
        strBuffer.reserve(cchBuffer);
-       strBuffer.resize(cchLength);
-       LPTSTR pBuffer = &*strBuffer.begin() + cchHead;
-       CopyMemory(pBuffer, pchTail, cchTail * sizeof(TCHAR));
-       return cchLength;
+       strBuffer.append(pchTail, cchTail);
 }
 
 /**
@@ -461,9 +461,8 @@ static void RecordZero(UniFile::txtstats & txstats, int offset)
  */
 BOOL UniMemFile::ReadString(String & line, String & eol, bool * lossy)
 {
-       line.clear();
-       eol.clear();
-       int cchLine = 0;
+       line.erase();
+       eol.erase();
        LPCTSTR pchLine = (LPCTSTR)m_current;
        
        // shortcut methods in case file is in the same encoding as our Strings
@@ -471,6 +470,7 @@ BOOL UniMemFile::ReadString(String & line, String & eol, bool * lossy)
 #ifdef _UNICODE
        if (m_unicoding == ucr::UCS2LE)
        {
+               int cchLine = 0;
                // If there aren't any wchars left in the file, return FALSE to indicate EOF
                if (m_current - m_base + 1 >= m_filesize)
                        return FALSE;
@@ -516,6 +516,7 @@ BOOL UniMemFile::ReadString(String & line, String & eol, bool * lossy)
 #else
        if (m_unicoding == ucr::NONE && EqualCodepages(m_codepage, getDefaultCodepage()))
        {
+               int cchLine = 0;
                // If there aren't any bytes left in the file, return FALSE to indicate EOF
                if (m_current - m_base >= m_filesize)
                        return FALSE;
@@ -706,7 +707,7 @@ BOOL UniMemFile::ReadString(String & line, String & eol, bool * lossy)
                                ++m_lineno;
                        return TRUE;
                }
-               cchLine = Append(line, cchLine, sch.c_str(), sch.length());
+               Append(line, sch.c_str(), sch.length());
        }
        return TRUE;
 }