From f40490c04914d9d4859d5c87cbe9417e7e36067b Mon Sep 17 00:00:00 2001
From: baldurk <baldurk@baldurk.org>
Date: Fri, 5 Jun 2020 19:36:02 +0100
Subject: [PATCH] Avoid underflow when calculating padding bytes

---
 qrenderdoc/Code/BufferFormatter.cpp | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/qrenderdoc/Code/BufferFormatter.cpp b/qrenderdoc/Code/BufferFormatter.cpp
index 808b8fc8a..c1717b6c0 100644
--- a/qrenderdoc/Code/BufferFormatter.cpp
+++ b/qrenderdoc/Code/BufferFormatter.cpp
@@ -933,11 +933,12 @@ QString BufferFormatter::DeclareStruct(QList<QString> &declaredStructs, const QS
       lastMemberStart += lastChild->byteOffset;
     }
 
-    const uint32_t size = GetVarSize(*lastChild);
-    uint32_t padBytes = requiredByteStride - (lastMemberStart + size);
+    const uint32_t structEnd = lastMemberStart + GetVarSize(*lastChild);
 
-    if(padBytes > 0)
-      ret += lit("    ") + DeclarePaddingBytes(padBytes);
+    if(requiredByteStride > structEnd)
+      ret += lit("    ") + DeclarePaddingBytes(requiredByteStride - structEnd);
+    else
+      qCritical() << "Unexpected stride overlow at struct" << name;
   }
 
   ret += lit("}\n");