floatscan: fix incorrect count of leading nonzero digits

this off-by-one error was causing values with just one digit past the
decimal point to be treated by the integer case. in many cases it
would yield the correct result, but if expressions are evaluated in
excess precision, double rounding may occur.

diff --git a/src/internal/floatscan.c b/src/internal/floatscan.c
index 10123bfa4437ba64c0a15b664f4a48d9da2f6f64..377a008bd86600602c6d1fd877c47f2fa6b26626 100644 (file)
--- a/src/internal/floatscan.c
+++ b/src/internal/floatscan.c
@@ -81,8 +81,8 @@ static long double decfloat(FILE *f, int c, int bits, int emin, int sign, int po
                        if (lrp!=-1) break;
                        lrp = dc;
                } else if (k < KMAX-2) {
-                       if (c!='0') lnz = dc;
                        dc++;
+                       if (c!='0') lnz = dc;
                        if (j) x[k] = x[k]*10 + c-'0';
                        else x[k] = c-'0';
                        if (++j==9) {