Integer Overflow in sprintf Buffer

include/reHDD.h

@@ -31,7 +31,7 @@
 #endif
 
 // Logic
-// #define DRYRUN    // don't touch the drives
+#define DRYRUN    // don't touch the drives
 #define FROZEN_ALERT // show alert if drive is frozen
 #define ZERO_CHECK   // check drive after shred if all bytes are zero, show alert if this fails
 

src/drive.cpp

@@ -62,8 +62,8 @@ string Drive::sCapacityToText()
         dSize /= 1000;
         u16UnitIndex++;
     }
-
-    sprintf(acBuffer, "%.*f %s", u16UnitIndex - 3, dSize, units[u16UnitIndex]);
+    int precision = (u16UnitIndex >= 3) ? (u16UnitIndex - 3) : 0;
+    sprintf(acBuffer, "%.*f %s", precision, dSize, units[u16UnitIndex]);
     return acBuffer;
 }