From 449f006f3a593504574d95313267690bee3945b4 Mon Sep 17 00:00:00 2001
From: Tillman Staffen <staffen@b-rex.de>
Date: Fri, 13 Mar 2026 11:35:10 +0100
Subject: [PATCH] [RECOMPILE] Changed STT Word Replacment to only replace
 complete words

---
 .../AvatarCore_STT/Private/STTManagerBase.cpp | 36 +++++++++++++++++--
 1 file changed, 34 insertions(+), 2 deletions(-)

diff --git a/Unreal/Plugins/AvatarCore_STT/Source/AvatarCore_STT/Private/STTManagerBase.cpp b/Unreal/Plugins/AvatarCore_STT/Source/AvatarCore_STT/Private/STTManagerBase.cpp
index d85c28d..b7399eb 100644
--- a/Unreal/Plugins/AvatarCore_STT/Source/AvatarCore_STT/Private/STTManagerBase.cpp
+++ b/Unreal/Plugins/AvatarCore_STT/Source/AvatarCore_STT/Private/STTManagerBase.cpp
@@ -420,9 +420,41 @@ FString USTTManagerBase::CheckForWordReplacement(const FString& InputText)
 
 	for(const FSTTWordReplacement& Replacement : ProcessorConfig->BaseSettings.STTReplacements)
 	{
-		for(const FString TranscribedWord : Replacement.TranscribedWords)
+		for(const FString& TranscribedWord : Replacement.TranscribedWords)
 		{
-			ResultString = ResultString.Replace(*TranscribedWord, *Replacement.ReplacementWord, ESearchCase::IgnoreCase);
+			if (TranscribedWord.IsEmpty())
+				continue;
+
+			const int32 MatchLen = TranscribedWord.Len();
+			FString Output;
+			Output.Reserve(ResultString.Len());
+
+			int32 SearchStart = 0;
+			while (SearchStart <= ResultString.Len() - MatchLen)
+			{
+				const int32 FoundIdx = ResultString.Find(TranscribedWord, ESearchCase::IgnoreCase, ESearchDir::FromStart, SearchStart);
+				if (FoundIdx == INDEX_NONE)
+					break;
+
+				// Check word boundaries: reject if immediately preceded or followed by an alpha character
+				const bool bPrecededByAlpha = (FoundIdx > 0) && FChar::IsAlpha(ResultString[FoundIdx - 1]);
+				const bool bFollowedByAlpha = (FoundIdx + MatchLen < ResultString.Len()) && FChar::IsAlpha(ResultString[FoundIdx + MatchLen]);
+
+				if (bPrecededByAlpha || bFollowedByAlpha)
+				{
+					Output += ResultString.Mid(SearchStart, FoundIdx - SearchStart + 1);
+					SearchStart = FoundIdx + 1;
+				}
+				else
+				{
+					Output += ResultString.Mid(SearchStart, FoundIdx - SearchStart);
+					Output += Replacement.ReplacementWord;
+					SearchStart = FoundIdx + MatchLen;
+				}
+			}
+
+			Output += ResultString.Mid(SearchStart);
+			ResultString = MoveTemp(Output);
 		}
 	}
 	return ResultString;