fully implement nul termination for LINE_READER::ReadLine()

common/dsnlexer.cpp

@@ -86,10 +86,11 @@ void DSNLEXER::PushReader( LINE_READER* aLineReader )
 {
     readerStack.push_back( aLineReader );
     reader = aLineReader;
+    start  = (char*) (*reader);
 
     // force a new readLine() as first thing.
-    limit = start();
-    next  = start();
+    limit = start;
+    next  = start;
 }
 
 
@@ -101,10 +102,11 @@ bool DSNLEXER::PopReader()
         readerStack.pop_back();
 
         reader = &readerStack.back();
+        start  = (char*) (*reader);
 
         // force a new readLine() as first thing.
-        limit = start();
-        next  = start();
+        limit = start;
+        next  = start;
         return true;
     }
     return false;
@@ -331,7 +333,7 @@ L_read:
                 goto exit;
             }
 
-            cur = start();
+            cur = start;
 
             // skip leading whitespace
             while( cur<limit && isSpace(*cur) )
@@ -345,8 +347,8 @@ L_read:
                 {
                     // save the entire line, including new line as the current token.
                     // the '#' character may not be at offset zero.
-                    curText = start();      // entire line is the token
-                    cur     = start();      // ensure a good curOffset below
+                    curText = start;      // entire line is the token
+                    cur     = start;      // ensure a good curOffset below
                     curTok  = DSN_COMMENT;
                     head    = limit;        // do a readLine() on next call in here.
                     goto exit;
@@ -414,7 +416,7 @@ L_read:
             like:  U2-14 or "U2"-"14"
             This is detectable by a non-space immediately preceeding the dash.
         */
-        if( *cur == '-' && cur>start() && !isSpace( cur[-1] ) )
+        if( *cur == '-' && cur>start && !isSpace( cur[-1] ) )
         {
             curText = '-';
             curTok = DSN_DASH;
@@ -535,7 +537,7 @@ L_read:
 
 exit:   // single point of exit, no returns elsewhere please.
 
-    curOffset = cur - start();
+    curOffset = cur - start;
 
     next = head;
 

common/richio.cpp

@@ -47,8 +47,8 @@ LINE_READER::LINE_READER( unsigned aMaxLineLength )
     capacity = LINE_READER_LINE_INITIAL_SIZE;
 
     // but never go above user's aMaxLineLength, and leave space for trailing nul
-    if( capacity > aMaxLineLength-1 )
-        capacity = aMaxLineLength-1;
+    if( capacity > aMaxLineLength+1 )
+        capacity = aMaxLineLength+1;
 
     line = new char[capacity];
 
@@ -71,9 +71,10 @@ void LINE_READER::expandCapacity( unsigned newsize )
         // resize the buffer, and copy the original data
         char* bigger = new char[capacity];
 
-        wxASSERT( capacity >= length );
+        wxASSERT( capacity >= length+1 );
 
         memcpy( bigger, line, length );
+        bigger[length] = 0;
 
         delete[] line;
         line = bigger;
@@ -102,8 +103,8 @@ unsigned FILE_LINE_READER::ReadLine() throw (IOError)
         if( length == maxLineLength )
             throw IOError( _("Line length exceeded") );
 
-        // a normal line breaks here, once through
-        if( length < capacity-1 || line[length-1] == '\n' )
+        // a normal line breaks here, once through while loop
+        if( length+1 < capacity || line[length-1] == '\n' )
             break;
 
         expandCapacity( capacity * 2 );
@@ -130,12 +131,13 @@ unsigned STRING_LINE_READER::ReadLine() throw (IOError)
         if( length >= maxLineLength )
             throw IOError( _("Line length exceeded") );
 
-        if( length > capacity )
-            expandCapacity( length );
+        if( length+1 > capacity )
+            expandCapacity( length+1 );
 
         wxASSERT( ndx + length <= lines.length() );
 
         memcpy( line, &source[ndx], length );
+        line[length] = 0;
 
         ++lineNum;
         ndx += length;

include/dsnlexer.h

@@ -78,6 +78,7 @@ enum DSN_SYNTAX_T {
  */
 class DSNLEXER
 {
+    char*               start;
     char*               next;
     char*               limit;
 
@@ -99,20 +100,17 @@ class DSNLEXER
     const KEYWORD*      keywords;
     unsigned            keywordCount;
 
-    /// Use casting char* operator to get start of line, which is dynamic since reader
-    /// can be resizing its buffer at each reader->ReadLine() only.
-    char*               start() const { return (char*) (*reader); }
-
     void init();
 
     int readLine() throw (IOError)
     {
         unsigned len = reader->ReadLine();
 
-        // set next and limit to start() and start() + len.
-        // start() is constant until the next ReadLine(), which could resize and
+        // start may have changed in ReadLine(), which can resize and
         // relocate reader's line buffer.
-        next  = start();
+        start = (*reader);
+
+        next  = start;
         limit = next + len;
 
         return len;

include/richio.h

@@ -101,12 +101,12 @@ public:
     /**
      * Function ReadLine
      * reads a line of text into the buffer and increments the line number
-     * counter.  If the line is larger than the buffer size, then an exception
-     * is thrown.
+     * counter.  If the line is larger than aMaxLineLength passed to the
+     * constructor, then an exception is thrown.  The line is nul terminated.
      * @return unsigned - The number of bytes read, 0 at end of file.
-     * @throw IOError only when a line is too long.
+     * @throw IOError when a line is too long.
      */
-    virtual unsigned ReadLine() throw (IOError) = 0;
+    virtual unsigned ReadLine() throw( IOError ) = 0;
 
     /**
      * Function GetSource
@@ -181,15 +181,7 @@ public:
             fclose( fp );
     }
 
-    /**
-     * Function ReadLine
-     * reads a line of text into the buffer and increments the line number
-     * counter.  If the line is larger than the buffer size, then an exception
-     * is thrown.
-     * @return unsigned - The number of bytes read, 0 at end of file.
-     * @throw IOError only when a line is too long.
-     */
-    unsigned ReadLine() throw (IOError);
+    unsigned ReadLine() throw( IOError );   // see LINE_READER::ReadLine() description
 
     /**
      * Function Rewind
@@ -217,34 +209,26 @@ protected:
 public:
 
     /**
-     * Constructor STRING_LINE_READER( const std::string& aString )
+     * Constructor STRING_LINE_READER( const std::string&, const wxString& )
      *
      * @param aString is a source string consisting of one or more lines
      * of text, where multiple lines are separated with a '\n' character.
      * The last line does not necessarily need a trailing '\n'.
+     *
      * @param aSource describes the source of aString for error reporting purposes
      *  can be anything meaninful, such as wxT( "cliboard" ).
      */
     STRING_LINE_READER( const std::string& aString, const wxString& aSource ) :
-        LINE_READER( 4096 ),
+        LINE_READER( LINE_READER_LINE_DEFAULT_MAX ),
         lines( aString ),
         ndx( 0 )
     {
         // Clipboard text should be nice and _use multiple lines_ so that
         // we can report _line number_ oriented error messages when parsing.
-        // Therefore a line of 4096 characters max seems more than adequate.
         source = aSource;
     }
 
-    /**
-     * Function ReadLine
-     * reads a line of text into the buffer and increments the line number
-     * counter.  If the line is larger than the buffer size, then an exception
-     * is thrown.
-     * @return unsigned - The number of bytes read, 0 at end of file.
-     * @throw IOError only when a line is too long.
-     */
-    unsigned ReadLine() throw (IOError);
+     unsigned ReadLine() throw(IOError);    // see LINE_READER::ReadLine() description
 };