Fix infinite loop in wxGrid::PosToEdgeOfLine().

Return -1 from wxGridRowOperations::GetLineBefore(0) to ensure that we exit
the loop in wxGrid::PosToEdgeOfLine(). Doing this is the logical thing to do
as wxGridColumnOperations::GetLineBefore() already behaved like this and this
was is more expected than returning 0, as the function previously did for some
reason.

Closes #15035.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@73487 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

diff --git a/include/wx/generic/private/grid.h b/include/wx/generic/private/grid.h
index 921aea39d473c73a34b3909f505ed6c1c954bae7..3b21325aa0a95b0297b0256faa8a77906a22196a 100644 (file)
--- a/include/wx/generic/private/grid.h
+++ b/include/wx/generic/private/grid.h
@@ -553,7 +553,7 @@ public:
     // NB: As GetLineAt(), currently this is always identity for rows.
     virtual int GetLinePos(const wxGrid *grid, int line) const = 0;
 
-    // Return the index of the line just before the given one.
+    // Return the index of the line just before the given one or wxNOT_FOUND.
     virtual int GetLineBefore(const wxGrid* grid, int line) const = 0;
 
     // Get the row or column label window
@@ -626,7 +626,7 @@ public:
         { return line; } // TODO: implement row reordering
 
     virtual int GetLineBefore(const wxGrid* WXUNUSED(grid), int line) const
-        { return line ? line - 1 : line; }
+        { return line - 1; }
 
     virtual wxWindow *GetHeaderWindow(wxGrid *grid) const
         { return grid->GetGridRowLabelWindow(); }