From: Pasukhin Dmitry <dpasukhi@opencascade.com>
Date: Sat, 29 Nov 2025 21:54:09 +0000 (+0000)
Subject: Modeling - Fix out-of-range access in BSplCLib_Reverse function (#863)
X-Git-Url: http://git.dev.opencascade.org/gitweb/?a=commitdiff_plain;h=a91a0d189ae572df2cbeff770dcdd9d995bdc7e4;p=occt.git

Modeling - Fix out-of-range access in BSplCLib_Reverse function (#863)

- Added a conditional check `if (aL < aUpper)` to prevent accessing array elements beyond bounds when `aL` equals or exceeds `aUpper`
---

diff --git a/src/FoundationClasses/TKMath/BSplCLib/BSplCLib_CurveComputation.pxx b/src/FoundationClasses/TKMath/BSplCLib/BSplCLib_CurveComputation.pxx
index 0534d0afc9..bb9b6bf0ff 100644
--- a/src/FoundationClasses/TKMath/BSplCLib/BSplCLib_CurveComputation.pxx
+++ b/src/FoundationClasses/TKMath/BSplCLib/BSplCLib_CurveComputation.pxx
@@ -273,7 +273,10 @@ void BSplCLib_Reverse(Array& theArray, const Standard_Integer theL)
   const int aL     = aLower + (theL - aLower) % theArray.Length();
 
   std::reverse(&theArray(aLower), &theArray(aL) + 1);
-  std::reverse(&theArray(aL + 1), &theArray(aUpper) + 1);
+  if (aL < aUpper)
+  {
+    std::reverse(&theArray(aL + 1), &theArray(aUpper) + 1);
+  }
 }
 
 // Removes a knot from the B-spline curve