improved DLE encoder

@@ -12,3 +11,1 @@
-	}
-	size_t encodedIndex = 0, sourceIndex = 0;
-	uint8_t nextByte;
+    size_t minAllowedLen = 0;

@@ -15,1 +18,4 @@
+    if(minAllowedLen > maxDestLen) {
+        return STREAM_TOO_SHORT;
+    }
 	if (addStxEtx) {

@@ -17,1 +22,3 @@
-		++encodedIndex;
+	    size_t currentIdx = 0;
+	    if(not escapeStxEtx) {
+	        destStream[currentIdx++] = DLE_CHAR;

@@ -18,0 +23,4 @@
+	    if(not escapeStxEtx) {
+	        destStream[currentIdx++] = DLE_CHAR;
+	    }
+		destStream[currentIdx] = STX_CHAR;

@@ -70,0 +40,4 @@
+ReturnValue_t DleEncoder::encodeStreamEscaped(const uint8_t *sourceStream, size_t sourceLen,
+        uint8_t *destStream, size_t maxDestLen, size_t *encodedLen,
+        bool addStxEtx) {
+    size_t encodedIndex = 1;

@@ -70,0 +82,4 @@
+        ++sourceIndex;
+    }
+
+    if (sourceIndex == sourceLen and encodedIndex < maxDestLen) {

@@ -70,0 +121,4 @@
+        ++sourceIndex;
+    }
+
+    if (sourceIndex == sourceLen and encodedIndex < maxDestLen) {

@@ -76,3 +143,1 @@
-	uint8_t nextByte;
-	if (*sourceStream != STX_CHAR) {
-		return DECODING_ERROR;
+	size_t encodedIndex = 0;

@@ -125,0 +174,4 @@
+            and (sourceStream[encodedIndex] != STX_CHAR)) {
+        if (sourceStream[encodedIndex] == DLE_CHAR) {
+            if(encodedIndex + 1 >= sourceStreamLen) {
+                return DECODING_ERROR;

@@ -125,0 +192,4 @@
+                    destStream[decodedIndex] = nextByte - 0x40;
+                }
+                else {
+                    return DECODING_ERROR;

@@ -125,0 +229,4 @@
+            }
+            nextByte = sourceStream[encodedIndex + 1];
+            if(nextByte == STX_CHAR) {
+                *readLen = ++encodedIndex;

@@ -125,0 +245,4 @@
+                return RETURN_OK;
+            }
+            else {
+                return DECODING_ERROR;

@@ -125,0 +254,4 @@
+        ++encodedIndex;
+        ++decodedIndex;
+    }
+    return DECODING_ERROR;