Exchanging the type of 'value' from 'long' to 'double' prevents overflow when parsing float values.

However, we still need to ensure against too large values contained in streams. This should be possible because the maximum length of a float value pre-comma is known to be 38 digits (FLT_MAX_10_EXP).

Author: aentinger

api/Stream.cpp

@@ -24,6 +24,7 @@
 
 #include "Common.h"
 #include "Stream.h"
+#include <math.h>
 
 #define PARSE_TIMEOUT 1000  // default number of milli-seconds to wait
 
@@ -162,9 +163,9 @@ float Stream::parseFloat(LookaheadMode lookahead, char ignore)
 {
   bool isNegative = false;
   bool isFraction = false;
-  long value = 0;
+  double value = 0.0;
   int c;
-  float fraction = 1.0;
+  unsigned int digits_post_comma = 0;
 
   c = peekNextDigit(lookahead, true);
     // ignore non numeric leading characters
@@ -181,7 +182,7 @@ float Stream::parseFloat(LookaheadMode lookahead, char ignore)
     else if(c >= '0' && c <= '9')  {      // is c a digit?
       value = value * 10 + c - '0';
       if(isFraction)
-         fraction *= 0.1;
+         digits_post_comma++;
     }
     read();  // consume the character we got with peek
     c = timedPeek();
@@ -190,10 +191,11 @@ float Stream::parseFloat(LookaheadMode lookahead, char ignore)
 
   if(isNegative)
     value = -value;
+
   if(isFraction)
-    return value * fraction;
-  else
-    return value;
+    value /= pow(10, digits_post_comma);
+
+  return value;
 }
 
 // read characters from stream into buffer