diff --git a/src/core/pistring.cpp b/src/core/pistring.cpp
index e3948881..bf9b14bf 100755
--- a/src/core/pistring.cpp
+++ b/src/core/pistring.cpp
@@ -255,6 +255,18 @@ void PIString::buildData(const char * cp) const {
 }
 
 
+void PIString::trimsubstr(int &st, int &fn) const {
+	for (int i = 0; i < length(); ++i)
+		if (at(i) != ' ' && at(i) != '\t' && at(i) != '\n' && at(i) != '\r' && at(i) != char(12))
+			{st = i; break;}
+	if (st < 0) return;
+	for (int i = length() - 1; i >= 0; --i)
+		if (at(i) != ' ' && at(i) != '\t' && at(i) != '\n' && at(i) != '\r' && at(i) != char(12))
+			{fn = i; break;}
+	piCout << "trim" << st << fn;
+}
+
+
 const char * PIString::dataConsole() const {
 	buildData(
 #ifdef PIP_ICU
@@ -459,14 +471,12 @@ PIString & PIString::cutMid(const int start, const int len) {
 
 
 PIString & PIString::trim() {
-	int st = 0, fn = 0;
-	for (int i = 0; i < length(); ++i)
-		if (at(i) != ' ' && at(i) != '\t' && at(i) != '\n' && at(i) != '\r' && at(i) != char(12))
-			{st = i; break;}
-	for (int i = length() - 1; i >= 0; --i)
-		if (at(i) != ' ' && at(i) != '\t' && at(i) != '\n' && at(i) != '\r' && at(i) != char(12))
-			{fn = i; break;}
-	//*this = mid(st, fn - st + 1);
+	int st = -1, fn = 0;
+	trimsubstr(st, fn);
+	if (st < 0) {
+		clear();
+		return *this;
+	}
 	if (fn < size_s() - 1) cutRight(size_s() - fn - 1);
 	if (st > 0) cutLeft(st);
 	return *this;
@@ -474,13 +484,9 @@ PIString & PIString::trim() {
 
 
 PIString PIString::trimmed() const {
-	int st = 0, fn = 0;
-	for (int i = 0; i < length(); ++i)
-		if (at(i) != ' ' && at(i) != '\t' && at(i) != '\n' && at(i) != '\r' && at(i) != char(12))
-			{st = i; break;}
-	for (int i = length() - 1; i >= 0; --i)
-		if (at(i) != ' ' && at(i) != '\t' && at(i) != '\n' && at(i) != '\r' && at(i) != char(12))
-			{fn = i; break;}
+	int st = -1, fn = 0;
+	trimsubstr(st, fn);
+	if (st < 0) return PIString();
 	return mid(st, fn - st + 1);
 }
 
diff --git a/src/core/pistring.h b/src/core/pistring.h
index 172f953d..fb7b6c82 100755
--- a/src/core/pistring.h
+++ b/src/core/pistring.h
@@ -799,7 +799,7 @@ private:
 		} else
 			if (base < 2 || base > 40) {if (ok != 0) *ok = false; return 0;}
 		//v.reverse();
-		if (ok != 0) *ok = true;
+		if (ok) *ok = true;
 		PIVector<int> digits;
 		llong ret = 0, m = 1;
 		bool neg = false;
@@ -807,7 +807,10 @@ private:
 		for (int i = 0; i < v.size_s(); ++i) {
 			if (v[i] == PIChar('-')) {neg = !neg; continue;}
 			cs = fromBaseN[int(v[i].toAscii())];
-			if (cs < 0 || cs >= base) break;
+			if (cs < 0 || cs >= base) {
+				if (ok) *ok = false;
+				break;
+			}
 			digits << cs;
 		}
 		for (int i = digits.size_s() - 1; i >= 0; --i) {
@@ -827,6 +830,7 @@ private:
 	}
 	void appendFromChars(const char * c, int s, const char * cp = 0);
 	void buildData(const char * cp = 0) const;
+	void trimsubstr(int &st, int &fn) const;
 	std::string convertToStd() const;
 #ifdef HAS_LOCALE
 	wstring convertToWString() const {wstring s; for (int i = 0; i < length(); ++i) s.push_back(at(i).toWChar()); return s;}