From afc93f39ce1a0a1c88789dfb3aedc5b8e3696e87 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Lucie=20G=C3=A9rard?= <lucie.gerard@qt.io>
Date: Tue, 26 May 2026 16:15:24 +0200
Subject: [PATCH] Natvis: trim leading/trailing whitespace from DisplayString
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Visual Studio trims whitespace from DisplayString inner XML text before
processing. MIEngine did not, causing multi-line DisplayStrings to render
as blank on GDB/LLDB — the leading newline and indentation made the
display appear empty in the variables panel.

Fix: call format.Trim() at the top of FormatValue() before processing.
---
 src/MIDebugEngine/Natvis.Impl/Natvis.cs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/MIDebugEngine/Natvis.Impl/Natvis.cs b/src/MIDebugEngine/Natvis.Impl/Natvis.cs
index edf7f702a..fdd8a8001 100755
--- a/src/MIDebugEngine/Natvis.Impl/Natvis.cs
+++ b/src/MIDebugEngine/Natvis.Impl/Natvis.cs
@@ -1264,6 +1264,7 @@ private string FormatValue(string format, IVariableInformation variable, IDictio
             {
                 return String.Empty;
             }
+            format = format.Trim();
             StringBuilder value = new StringBuilder();
             for (int i = 0; i < format.Length; ++i)
             {