From 10b2055eb6f12dd16d34bcee612bba2b8073a131 Mon Sep 17 00:00:00 2001
From: RealMalWare <39832934+RealMalWare@users.noreply.github.com>
Date: Fri, 15 May 2026 02:13:35 +0200
Subject: [PATCH] Refactor multi-selection expression evaluation logic

---
 src/Notepad3.c | 99 ++++++++++++++++++++++++++++++++++++--------------
 1 file changed, 71 insertions(+), 28 deletions(-)

diff --git a/src/Notepad3.c b/src/Notepad3.c
index c3ca0f3c5..3c2e9b815 100644
--- a/src/Notepad3.c
+++ b/src/Notepad3.c
@@ -10875,38 +10875,81 @@ static void  _CalculateStatusbarSections(int vSectionWidth[], sectionTxt_t tchSt
 static double _InterpMultiSelectionTinyExpr(te_int_t* piExprError)
 {
 #define _tmpBufCnt 128
-    char tmpRectSelN[_tmpBufCnt] = { '\0' };
+	char tmpRectSelN[_tmpBufCnt] = { '\0' };
 
-    DocPosU const selCount = SciCall_GetSelections();
-    int const calcBufSize = (int)(_tmpBufCnt * selCount + 1);
-    char * const calcBuffer = (char*)AllocMem(calcBufSize, HEAP_ZERO_MEMORY);
-    WCHAR * const calcBufferW = (WCHAR*)AllocMem(calcBufSize * sizeof(WCHAR), HEAP_ZERO_MEMORY);
+	DocPosU const selCount = SciCall_GetSelections();
+	int const calcBufSize = (int)(_tmpBufCnt * selCount + 1);
+	char * const calcBuffer = (char*)AllocMem(calcBufSize, HEAP_ZERO_MEMORY);
+	WCHAR * const calcBufferW = (WCHAR*)AllocMem(calcBufSize * sizeof(WCHAR), HEAP_ZERO_MEMORY);
 
-    bool bLastCharWasDigit = false;
-    for (DocPosU i = 0; i < selCount; ++i) {
-        DocPos const posSelStart = SciCall_GetSelectionNStart(i);
-        DocPos const posSelEnd = SciCall_GetSelectionNEnd(i);
-        size_t const cchToCopy = (size_t)(posSelEnd - posSelStart);
-        StringCchCopyNA(tmpRectSelN, _tmpBufCnt, SciCall_GetRangePointer(posSelStart, (DocPos)cchToCopy), cchToCopy);
-        StrTrimA(tmpRectSelN, " ");
+	size_t bufPos = 0;
+	bool bLastCharWasDigit = false;
+	bool bAllPlainNumbers = true;
+	bool bHasValue = false;
+	double numberSum = 0.0;
 
-        char const defchar = (char)0x24;
-        MultiByteToWideChar(Encoding_SciCP, 0, calcBuffer, -1, calcBufferW, calcBufSize);
-        WideCharToMultiByte(1252, (WC_COMPOSITECHECK | WC_DISCARDNS), calcBufferW, -1, calcBuffer, calcBufSize, &defchar, NULL);
-        StrDelChrA(calcBuffer, chr_currency);
+	for (DocPosU i = 0; i < selCount; ++i) {
+		DocPos const posSelStart = SciCall_GetSelectionNStart(i);
+		DocPos const posSelEnd = SciCall_GetSelectionNEnd(i);
+		size_t const cchToCopy = (size_t)(posSelEnd - posSelStart);
+		StringCchCopyNA(tmpRectSelN, _tmpBufCnt, SciCall_GetRangePointer(posSelStart, (DocPos)cchToCopy), cchToCopy);
+		StrTrimA(tmpRectSelN, " ");
 
-        if (!StrIsEmptyA(tmpRectSelN)) {
-            if (IsDigitA(tmpRectSelN[0]) && bLastCharWasDigit) {
-                StringCchCatA(calcBuffer, SizeOfMem(calcBuffer), "+"); // default: add numbers
-            }
-            bLastCharWasDigit = IsDigitA(tmpRectSelN[StringCchLenA(tmpRectSelN,COUNTOF(tmpRectSelN)) - 1]);
-            StringCchCatA(calcBuffer, SizeOfMem(calcBuffer), tmpRectSelN);
-        }
-    }
-    double const result = te_interp(calcBuffer, piExprError);
-    FreeMem(calcBufferW);
-    FreeMem(calcBuffer);
-    return result;
+		if (!StrIsEmptyA(tmpRectSelN)) {
+			char tmpNumber[_tmpBufCnt] = { '\0' };
+			StringCchCopyA(tmpNumber, COUNTOF(tmpNumber), tmpRectSelN);
+			StrDelChrA(tmpNumber, chr_currency);
+
+			char *pEnd = NULL;
+			double const numberValue = strtod(tmpNumber, &pEnd);
+
+			if (pEnd && pEnd != tmpNumber) {
+				while (*pEnd == ' ' || *pEnd == '\t') {
+					++pEnd;
+				}
+
+				if (*pEnd == '\0') {
+					numberSum += numberValue;
+					bHasValue = true;
+				} else {
+					bAllPlainNumbers = false;
+				}
+			} else {
+				bAllPlainNumbers = false;
+			}
+
+			size_t const lenN = StringCchLenA(tmpRectSelN, COUNTOF(tmpRectSelN));
+
+			if (bufPos < (size_t)calcBufSize && lenN + 2 <= ((size_t)calcBufSize - bufPos)) {
+				if (IsDigitA(tmpRectSelN[0]) && bLastCharWasDigit) {
+					calcBuffer[bufPos++] = '+';
+				}
+
+				memcpy(calcBuffer + bufPos, tmpRectSelN, lenN);
+				bufPos += lenN;
+				calcBuffer[bufPos] = '\0';
+
+				bLastCharWasDigit = IsDigitA(tmpRectSelN[lenN - 1]);
+			}
+		}
+	}
+
+	if (bAllPlainNumbers && bHasValue) {
+		*piExprError = 0;
+		FreeMem(calcBufferW);
+		FreeMem(calcBuffer);
+		return numberSum;
+	}
+
+	char const defchar = (char)0x24;
+	MultiByteToWideChar(Encoding_SciCP, 0, calcBuffer, -1, calcBufferW, calcBufSize);
+	WideCharToMultiByte(1252, (WC_COMPOSITECHECK | WC_DISCARDNS), calcBufferW, -1, calcBuffer, calcBufSize, &defchar, NULL);
+	StrDelChrA(calcBuffer, chr_currency);
+
+	double const result = te_interp(calcBuffer, piExprError);
+	FreeMem(calcBufferW);
+	FreeMem(calcBuffer);
+	return result;
 }