Nikolay Sivov : dwrite: Avoid possible out-of-bounds cluster metrics access.

[Alexandre Julliard]

Module: wine
Branch: stable
Commit: 68bf2fa07328f62ee8d61a13931e5820ed1d9a89
URL:    https://source.winehq.org/git/wine.git/?a=commit;h=68bf2fa07328f62ee8d61a13931e5820ed1d9a89

Author: Nikolay Sivov <nsivov at codeweavers.com>
Date:   Mon Aug 13 11:22:06 2018 +0300

dwrite: Avoid possible out-of-bounds cluster metrics access.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=45535
Signed-off-by: Nikolay Sivov <nsivov at codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard at winehq.org>
(cherry picked from commit 470ed3c559c89d7bc9ee3fd3a9afbf19ea6e7aad)
Signed-off-by: Michael Stefaniuc <mstefani at winehq.org>

---

 dlls/dwrite/layout.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/dlls/dwrite/layout.c b/dlls/dwrite/layout.c
index 104b039..1218ee8 100644
--- a/dlls/dwrite/layout.c
+++ b/dlls/dwrite/layout.c
@@ -2089,7 +2089,7 @@ static HRESULT layout_compute_effective_runs(struct dwrite_textlayout *layout)
     */
     if (layout->len == 0)
         hr = layout_set_dummy_line_metrics(layout, 0);
-    else if (layout->clustermetrics[layout->cluster_count - 1].isNewline)
+    else if (layout->cluster_count && layout->clustermetrics[layout->cluster_count - 1].isNewline)
         hr = layout_set_dummy_line_metrics(layout, layout->len - 1);
     if (FAILED(hr))
         return hr;