Fix crash when row did rebreak while drawing (fix #351).

git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@4122 a592a061-630c-0410-9148-cb99ea01b6c8

src/ChangeLog

@@ -1,3 +1,20 @@
+2002-05-03  Juergen Vigna  <jug@sad.it>
+
+	* screen.C (drawFromTo): recalculate the rowpointer if we had a
+	change in LyXText as we can not be sure it was not freed.
+	(drawOneRow): remove unused code.
+
+	* text.C (drawInset): redo the calculation of the need_break_row as
+	it could have a row which was already freed.
+	(draw): look at the return value of drawInset and return false if
+	it also returned false.
+	(paintRowText): look at the return value of draw and return false if
+	it also returned false.
+
+	* lyxtext.h: added bool return type to drawInset() and draw() so that
+	if we have a change in the row so that the rowbreak has to be redone
+	we abort drawing as it will be called again.
+
 2002-05-02  Juergen Vigna  <jug@sad.it>
 
 	* BufferView_pimpl.C (moveCursorUpdate): make repaint if we had

src/lyxtext.h

@@ -648,11 +648,11 @@ private:
 	/// draw a mark for foreign language, starting from orig_x
 	void drawForeignMark(DrawRowParams & p, float const orig_x, LyXFont const & orig_font);
 	/// draw an inset
-	void drawInset(DrawRowParams & p, lyx::pos_type const pos);
+	bool drawInset(DrawRowParams & p, lyx::pos_type const pos);
 	/// draw new line marker
 	void drawNewline(DrawRowParams & p, lyx::pos_type const pos);
 	/// draw text
-	void draw(DrawRowParams & p, lyx::pos_type & vpos);
+	bool draw(DrawRowParams & p, lyx::pos_type & vpos);
 
 	/// get the next breakpoint in a given paragraph
 	lyx::pos_type nextBreakPoint(BufferView *, Row const * row, int width) const;

src/screen.C

@@ -135,6 +135,11 @@ void LyXScreen::drawFromTo(LyXText * text, BufferView * bv,
 			text->setCursor(bv, text->cursor.par(),
 					text->cursor.pos());
 			text->status(bv, st);
+			// we should be sure our row-pointer is still valid, so it's
+			// better to recompute it.
+			y_text = y + text->first_y;
+			row = text->getRowNearY(y_text);
+			y = y_text - text->first_y;
 			text->getVisibleRow(bv, y + y_offset,
 					    x_offset, row, y + text->first_y);
 		}
@@ -161,18 +166,7 @@ void LyXScreen::drawOneRow(LyXText * text, BufferView * bv, Row * row,
 	if (((y + row->height()) > 0) &&
 	    ((y - row->height()) <= static_cast<int>(owner.height()))) {
 		// ok there is something visible
-#if 0
-		LyXText::text_status st = bv->text->status();
-		do {
-			bv->text->status(bv, st);
-			text->getVisibleRow(bv, y, x_offset, row,
-					    y + text->first_y);
-		} while (!text->inset_owner &&
-			 text->status() == LyXText::CHANGED_IN_DRAW);
-		bv->text->status(bv, st);
-#else
 		text->getVisibleRow(bv, y, x_offset, row, y + text->first_y);
-#endif
 	}
 	force_clear = false;
 }

src/text.C

@@ -475,23 +475,25 @@ void LyXText::drawNewline(DrawRowParams & p, pos_type const pos)
 }
 
 
-void LyXText::drawInset(DrawRowParams & p, pos_type const pos)
+bool LyXText::drawInset(DrawRowParams & p, pos_type const pos)
 {
 	Inset * inset = p.row->par()->getInset(pos);
 
 	// FIXME: shouldn't happen
 	if (!inset) {
-		return;
+		return true;
 	}
 
 	LyXFont const & font = getFont(p.bv->buffer(), p.row->par(), pos);
+	// we need this here as the row pointer may be illegal
+	// at a later time (Jug20020502)
+	Row * prev = p.row->previous();
 
 	inset->update(p.bv, font, false);
 	inset->draw(p.bv, font, p.yo + p.row->baseline(), p.x, p.cleared);
 
 	if (!need_break_row && !inset_owner
 	    && p.bv->text->status() == CHANGED_IN_DRAW) {
-		Row * prev = p.row->previous();
 		if (prev && prev->par() == p.row->par()) {
 			breakAgainOneRow(p.bv, prev);
 			if (prev->next() != p.row) {
@@ -501,11 +503,15 @@ void LyXText::drawInset(DrawRowParams & p, pos_type const pos)
 			} else {
 				need_break_row = p.row;
 			}
+		} else if (!prev) {
+			need_break_row = firstrow;
 		} else {
-			need_break_row = p.row;
+			need_break_row = prev->next();
 		}
 		setCursor(p.bv, cursor.par(), cursor.pos());
+		return false;
 	}
+	return true;
 }
 
 
@@ -630,7 +636,7 @@ void LyXText::drawChars(DrawRowParams & p, pos_type & vpos,
 }
 
 
-void LyXText::draw(DrawRowParams & p, pos_type & vpos)
+bool LyXText::draw(DrawRowParams & p, pos_type & vpos)
 {
 	pos_type const pos = vis2log(vpos);
 	Paragraph * par = p.row->par();
@@ -644,12 +650,13 @@ void LyXText::draw(DrawRowParams & p, pos_type & vpos)
 	if (IsNewlineChar(c)) {
 		++vpos;
 		drawNewline(p, pos);
-		return;
+		return true;
 	} else if (IsInsetChar(c)) {
-		drawInset(p, pos);
+		if (!drawInset(p, pos))
+			return false;
 		++vpos;
 		drawForeignMark(p, orig_x, orig_font);
-		return;
+		return true;
 	}
 
 	// usual characters, no insets
@@ -681,6 +688,7 @@ void LyXText::draw(DrawRowParams & p, pos_type & vpos)
 		lyxerr << "No this shouldn't happen!\n";
 #endif
 #endif
+	return true;
 }
 
 
@@ -3662,7 +3670,8 @@ void LyXText::paintRowText(DrawRowParams & p)
 				p.x += p.separator;
 			++vpos;
 		} else {
-			draw(p, vpos);
+			if (!draw(p, vpos))
+				break;
 		}
 	}
 }