float.c: correct exponent capping

Actually enforce the exponent capping, as opposed to only enforcing it
to within a factor of 10.  Furthermore, continue to scan the string in
order to check for invalid characters.

Finally, 16384 is too tight of a bound for a binary exponent: it's a
tight bound, but the shift added due to the digit string can move the
cap into the active region (±16383).  Thus, change it to 20000 to be
on the safe side.

1 files changed, 3 insertions, 4 deletions

diff --git a/float.c b/float.c
index db641800..843dbdfa 100644
--- a/float.c
+++ b/float.c
@@ -141,9 +141,8 @@ static int32_t read_exponent(const char *string, int32_t max)
 	     * in single, double, and extended precision, but
 	     * sufficient to avoid signed integer wraparound.
 	     */
-	    if (i > max) {
-		break;
-	    }
+	    if (i > max)
+		i = max;
 	} else if (*string == '_') {
 	    /* do nothing */
 	} else {
@@ -494,7 +493,7 @@ static bool ieee_flconvert_hex(const char *string, uint16_t * mant,
             }
         } else if (c == 'p' || c == 'P') {
 	    int32_t e;
-	    e = read_exponent(string, 16384);
+	    e = read_exponent(string, 20000);
 	    if (e == INT32_MAX)
 		return false;
 	    twopwr += e;