Fix editing of text containing surrogate characters.

This relates to issue #162.

Signed-off-by: Michele Calgaro <michele.calgaro@yahoo.it>
(cherry picked from commit 9c648bea9bfb1113c070a05b36f78ff006d0877a)

1 files changed, 28 insertions, 5 deletions

diff --git a/src/kernel/qrichtext.cpp b/src/kernel/qrichtext.cpp
index 4609a340b..6f09cc185 100644
--- a/src/kernel/qrichtext.cpp
+++ b/src/kernel/qrichtext.cpp
@@ -221,12 +221,19 @@ TQTextCursor *TQTextDeleteCommand::execute( TQTextCursor *c )
     cursor.setParagraph( s );
     cursor.setIndex( index );
     int len = text.size();
+    
     if ( c )
 	*c = cursor;
     if ( doc ) {
 	doc->setSelectionStart( TQTextDocument::Temp, cursor );
 	for ( int i = 0; i < len; ++i )
+	{
+	    if (text[i].c.isHighSurrogate() && i < (len - 1) && text[i + 1].c.isLowSurrogate())
+	    {
+		++i; // This is required for correct advancement when handling surrogate pairs
+	    }
 	    cursor.gotoNextLetter();
+	}
 	doc->setSelectionEnd( TQTextDocument::Temp, cursor );
 	doc->removeSelectedText( TQTextDocument::Temp, &cursor );
 	if ( c )
@@ -1250,9 +1257,17 @@ bool TQTextCursor::removePreviousChar()
 {
     tmpX = -1;
     if ( !atParagStart() ) {
-	para->remove( idx-1, 1 );
+	if (para->at(idx - 1)->c.isLowSurrogate() && idx > 1 && para->at(idx - 2)->c.isHighSurrogate())
+	{
+	    para->remove(idx - 2, 2);
+	    idx -= 2;
+	}
+	else
+	{
+	    para->remove(idx - 1, 1);
+	    idx--;
+	}
 	int h = para->rect().height();
-	idx--;
 	// shouldn't be needed, just to make sure.
 	fixCursorPosition();
 	para->format( -1, TRUE );
@@ -4009,6 +4024,7 @@ int TQTextString::width( int idx ) const
 {
      int w = 0;
      TQTextStringChar *c = &at( idx );
+     // '!c->charStop' already takes care of low surrogate chars
      if ( !c->charStop || c->c.unicode() == 0xad || c->c.unicode() == 0x2028 )
 	 return 0;
 #ifndef TQT_NO_TEXTCUSTOMITEM
@@ -4292,10 +4308,10 @@ void TQTextParagraph::format( int start, bool doMove )
     if ( !str || str->length() == 0 || !formatter() )
 	return;
 
-    if ( hasdoc &&
-	 document()->preProcessor() &&
-	 ( needPreProcess || state == -1 ) )
+    if ( hasdoc && document()->preProcessor() && ( needPreProcess || state == -1 ) )
+    {
 	document()->preProcessor()->process( document(), this, invalid <= 0 ? 0 : invalid );
+    }
     needPreProcess = FALSE;
 
     if ( invalid == -1 )
@@ -5784,6 +5800,7 @@ int TQTextFormatterBreakWords::format( TQTextDocument *doc, TQTextParagraph *par
 	    lastChr = c->c;
 	    lastFormat = c->format();
 	}
+
 	bool lastWasOwnLineCustomItem = lastBreak == -2;
 	bool hadBreakableChar = lastBreak != -1;
 	bool lastWasHardBreak = lastChr == TQChar_linesep;
@@ -5793,6 +5810,12 @@ int TQTextFormatterBreakWords::format( TQTextDocument *doc, TQTextParagraph *par
 	    c->format()->setPainter( painter );
 	c = &string->at( i );
 
+	// Skip over low surrogate chars
+	if (c->c.isLowSurrogate())
+	{
+	    continue;
+	}
+
 	if (lastFormat != c->format() && !c->c.isSpace()
 	    && lastFormat->font().italic() && !c->format()->font().italic()) {
 	    int rb = lastFormat->fontMetrics().rightBearing(lastChr);