changes requested in review (#72)

display.c

@@ -164,7 +164,7 @@ void exitCurses(void)
 
 static void printaddr(uint64_t addr)
 {
-  char templ[7];
+  char templ[7]; // maximum string is "%016lX", which is 6 chars + 1 null byte
   sprintf(templ,"%%0%dlX", nAddrDigits);
   PRINTW((templ, addr));
 }

file.c

@@ -16,6 +16,26 @@
    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.*/
 #include "hexedit.h"
 
+
+// Compute number of hex-digits needed to display an address.
+// We only increase this by full bytes (2 digits).
+// Because the input is uint64_t, the maximum result is 16 (64bit = 16*4bit).
+int compute_nDigits(uint64_t maxAddr)
+{
+  int digits = 0;
+  while (maxAddr) {
+    digits+=2;
+    maxAddr >>= 8;
+  }
+
+  if (digits==0) {
+    return 2;
+  }
+
+  return digits;
+}
+
+
 void openFile(void)
 {
   struct stat st;
@@ -54,16 +74,11 @@ void openFile(void)
   }
   biggestLoc = fileSize;
 
-  // compute number of digits for address
+  nAddrDigits = compute_nDigits(biggestLoc);
 
-  nAddrDigits=8;
-  off_t maxAddr = biggestLoc;
-  if (maxAddr > 0xFFFFFFFF) {
-    maxAddr >>= 32;
-    while (maxAddr) {
-      nAddrDigits+=2;
-      maxAddr >>= 8;
-    }
+  // use at least 8 digits (4 byte addresses)
+  if (nAddrDigits < 8) {
+    nAddrDigits = 8;
   }
 }