01/01: [MSPAINT] Fix divide by zero in drawZoomFrame

[Stanislav Motylkov]

https://git.reactos.org/?p=reactos.git;a=commitdiff;h=8c726ae0d23c9c02144b2…

commit 8c726ae0d23c9c02144b22a3706a100b3ae08c93
Author:     Stanislav Motylkov <x86corez(a)gmail.com>
AuthorDate: Thu May 24 00:31:20 2018 +0300
Commit:     Hermès BÉLUSCA - MAÏTO <hermes.belusca-maito(a)reactos.org>
CommitDate: Wed May 23 23:40:28 2018 +0200

    [MSPAINT] Fix divide by zero in drawZoomFrame
    
    CORE-14539 #resolve
---
 base/applications/mspaint/imgarea.cpp | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/base/applications/mspaint/imgarea.cpp
b/base/applications/mspaint/imgarea.cpp
index c9b1b3f49e..433fc7b04a 100644
--- a/base/applications/mspaint/imgarea.cpp
+++ b/base/applications/mspaint/imgarea.cpp
@@ -41,8 +41,14 @@ void CImgAreaWindow::drawZoomFrame(int mouseX, int mouseY)
     int x, y, w, h;
     scrollboxWindow.GetClientRect(&clientRectScrollbox);
     GetClientRect(&clientRectImageArea);
-    w = clientRectImageArea.right * clientRectScrollbox.right /
(clientRectImageArea.right * 2);
-    h = clientRectImageArea.bottom * clientRectScrollbox.bottom /
(clientRectImageArea.bottom * 2);
+    w = clientRectImageArea.right * 2;
+    h = clientRectImageArea.bottom * 2;
+    if (!w || !h)
+    {
+        return;
+    }
+    w = clientRectImageArea.right * clientRectScrollbox.right / w;
+    h = clientRectImageArea.bottom * clientRectScrollbox.bottom / h;
     x = max(0, min(clientRectImageArea.right - w, mouseX - w / 2));
     y = max(0, min(clientRectImageArea.bottom - h, mouseY - h / 2));