[patch] fixing segfault because of empty coord cache

[Stefan Schimanski]

Hi!

Here is a patch for a crash that happens due to a cell not in the coord cache during the drawing of the selection. It could be that this is related (and also fixes) http://bugzilla.lyx.org/show_bug.cgi? id=3715 .

You can trigger this crash in Beta 3 or 1.5svn like this:

New document, Ctrl-M \ref <space> <shift-right>



Stefan

Index: src/mathed/InsetMathNest.cpp
===================================================================
--- src/mathed/InsetMathNest.cpp        (Revision 18579)
+++ src/mathed/InsetMathNest.cpp        (Arbeitskopie)
@@ -251,11 +251,15 @@
                for (idx_type i = 0; i < nargs(); ++i) {
                        if (idxBetween(i, s1.idx(), s2.idx())) {
                                MathData const & c = cell(i);
-                               int x1 = c.xo(bv);
-                               int y1 = c.yo(bv) - c.ascent();
-                               int x2 = c.xo(bv) + c.width();
-                               int y2 = c.yo(bv) + c.descent();
-                               pi.pain.fillRectangle(x1, y1, x2 - x1, y2 - y1, 
Color::selection);
+                               // if the cell is not in the cache, it is 
probably not drawn,
+                               // and therefore not warmed up above. So skip 
the selection!
+                               if (bv.coordCache().arrays().has(&c)) {
+                                       int x1 = c.xo(bv);
+                                       int y1 = c.yo(bv) - c.ascent();
+                                       int x2 = c.xo(bv) + c.width();
+                                       int y2 = c.yo(bv) + c.descent();
+                                       pi.pain.fillRectangle(x1, y1, x2 - x1, 
y2 - y1, Color::selection);
+                               }
                        }
                }
        }

I believe the problem is when an inset derived from InsetMathNest does not draw all its cells, and hence a cell is not in the coord cache yet. Then the warm up call in InsetMathNest::drawSelection cannot get the cell into the cache and the loop over all cells at the bottom of this very function will trigger an assertion. With this patch the <shift-right> seems to have no effect. Haven't checked why. But at least the segfault is gone.

refcrash.patch
Description: Binary data

PGP.sig
Description: Signierter Teil der Nachricht