fix overread (consuming an extra byte) scanning NAN

[musl] / src / internal / floatscan.c

diff --git a/src/internal/floatscan.c b/src/internal/floatscan.c
index 0e1f6d0..b260381 100644 (file)
--- a/src/internal/floatscan.c
+++ b/src/internal/floatscan.c
@@ -44,7 +44,7 @@ static long long scanexp(FILE *f, int pok)
        }
        for (x=0; c-'0'<10U && x<INT_MAX/10; c = shgetc(f))
                x = 10*x + c-'0';
-       for (y=x; c-'0'<10U && x<LLONG_MAX/100; c = shgetc(f))
+       for (y=x; c-'0'<10U && y<LLONG_MAX/100; c = shgetc(f))
                y = 10*y + c-'0';
        for (; c-'0'<10U; c = shgetc(f));
        shunget(f);
@@ -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) {
@@ -394,31 +394,32 @@ static long double hexfloat(FILE *f, int bits, int emin, int sign, int pok)
        return scalbnl(y, e2);
 }
 
-long double __floatscan(FILE *f, int c, int prec, int pok)
+long double __floatscan(FILE *f, int prec, int pok)
 {
        int sign = 1;
        int i;
        int bits;
        int emin;
+       int c;
 
        switch (prec) {
        case 0:
-               bits = 24;
-               emin = -149;
+               bits = FLT_MANT_DIG;
+               emin = FLT_MIN_EXP-bits;
                break;
        case 1:
-               bits = 53;
-               emin = -1074;
+               bits = DBL_MANT_DIG;
+               emin = DBL_MIN_EXP-bits;
                break;
        case 2:
                bits = LDBL_MANT_DIG;
-               emin = -16445;
+               emin = LDBL_MIN_EXP-bits;
                break;
        default:
                return 0;
        }
 
-       if (c<0) c = shgetc(f);
+       while (isspace((c=shgetc(f))));
 
        if (c=='+' || c=='-') {
                sign -= 2*(c=='-');
@@ -428,13 +429,14 @@ long double __floatscan(FILE *f, int c, int prec, int pok)
        for (i=0; i<8 && (c|32)=="infinity"[i]; i++)
                if (i<7) c = shgetc(f);
        if (i==3 || i==8 || (i>3 && pok)) {
-               if (i==3) shunget(f);
-               if (pok) for (; i>3; i--) shunget(f);
-               else shlim(f, 0);
+               if (i!=8) {
+                       shunget(f);
+                       if (pok) for (; i>3; i--) shunget(f);
+               }
                return sign * INFINITY;
        }
        if (!i) for (i=0; i<3 && (c|32)=="nan"[i]; i++)
-               if (i<3) c = shgetc(f);
+               if (i<2) c = shgetc(f);
        if (i==3) {
                return NAN;
        }