diff --git a/Foundation/include/Poco/FIFOBuffer.h b/Foundation/include/Poco/FIFOBuffer.h
index 8ebe2cd4d..58fd92ae9 100644
--- a/Foundation/include/Poco/FIFOBuffer.h
+++ b/Foundation/include/Poco/FIFOBuffer.h
@@ -263,14 +263,10 @@ public:
 		/// 
 		/// Returns the length of data written.
 	{
-		std::size_t len = length;
+		if (length == 0 || length > buffer.size())
+			length = buffer.size();
 
-		if (len == 0)
-			len = buffer.size();
-		else if (len > buffer.size())
-			len = buffer.size();
-
-		return write(buffer.begin(), len);
+		return write(buffer.begin(), length);
 	}
 
 	std::size_t size() const
diff --git a/Foundation/src/NumericString.cpp b/Foundation/src/NumericString.cpp
index 2b087efed..b2975ce24 100644
--- a/Foundation/src/NumericString.cpp
+++ b/Foundation/src/NumericString.cpp
@@ -86,20 +86,16 @@ void insertThousandSep(std::string& str, char thSep, char decSep = '.')
 	/// Used only internally.
 {
 	poco_assert (decSep != thSep);
+	if (str.size() == 0) return;
 
 	std::string::size_type exPos = str.find('e');
+	if (exPos == std::string::npos) exPos = str.find('E');
 	std::string::size_type decPos = str.find(decSep);
 	// there's no rinsert, using forward iterator to go backwards
 	std::string::iterator it = str.end();
 	std::string::iterator begin = str.begin();
-	if (exPos != std::string::npos)
-	{
-		while (it != begin)
-		{
-			--it;
-			if ((*it == 'e') || (*it == 'E')) break;
-		}
-	}
+	if (exPos != std::string::npos) it -= str.size() - exPos;
+
 	if (decPos != std::string::npos)
 	{
 		while (it != begin)
@@ -109,14 +105,19 @@ void insertThousandSep(std::string& str, char thSep, char decSep = '.')
 		}
 	}
 	int thCount = 0;
-	for (; it != begin; --it)
+	if (it == str.end()) --it;
+	for (; it != begin;)
 	{
-		if (!std::isdigit(*it)) continue;
-		if (++thCount == 3)
-		{
-			it = str.insert(it, thSep);
-			thCount = 0;
-		}
+		std::string::iterator pos = it;
+		std::string::value_type chr = *it;
+		std::string::value_type prevChr = *--it;
+
+		if (!std::isdigit(chr)) continue;
+
+		if (++thCount == 3 && std::isdigit(prevChr))
+			it = str.insert(pos, thSep);
+
+		if (thCount == 3) thCount = 0;
 	}
 }
 
diff --git a/Foundation/testsuite/src/StringTest.cpp b/Foundation/testsuite/src/StringTest.cpp
index 9d4d86a46..a317c5413 100644
--- a/Foundation/testsuite/src/StringTest.cpp
+++ b/Foundation/testsuite/src/StringTest.cpp
@@ -594,6 +594,10 @@ void StringTest::testStringToDouble()
 			assert(strToDouble(format("12%c3456789012345678901234567890", ds), result, ds, ts));
 			assertEqualDelta(12.34, result, 0.01);
 
+			assert(strToDouble("1234345", result, ds, ts));
+			assertEqualDelta(1234345, result, 0.00000001);
+			assert(strToDouble(format("1%c234%c345", ts, ts), result, ds, ts));
+			assertEqualDelta(1234345, result, 0.00000001);
 			assert(strToDouble(format("1%c234%c3456789012345678901234567890", ts, ds), result, ds, ts));
 			assertEqualDelta(1234.3456789, result, 0.00000001);
 			assert(strToDouble(format("12%c345%c3456789012345678901234567890", ts, ds), result, ds, ts));
@@ -992,6 +996,11 @@ void StringTest::testFloatToString()
 	assert (doubleToStr(str, val, 2, 22, ',') == "-10,372,157,551,632.90");
 	assert (doubleToStr(str, val, 2, 22, '.', ',') == "-10.372.157.551.632,90");
 	assert (doubleToStr(str, val, 2, 22, ' ', ',') == "-10 372 157 551 632,90");
+
+	int ival = 1234567890;
+	assert(doubleToStr(str, ival, 1, 15, ',') == "1,234,567,890.0");
+	ival = -123456789;
+	assert(doubleToStr(str, ival, 1, 14, ',') == "-123,456,789.0");
 }