Add locale-independent number formatting and parsing functions.

4 files changed, 845 insertions, 40 deletions

diff --git a/source/fitz/dtoa.c b/source/fitz/dtoa.c
new file mode 100644
index 00000000..eaa3b713
--- /dev/null
+++ b/source/fitz/dtoa.c
@@ -0,0 +1,843 @@
+/* The authors of this software are Rob Pike and Ken Thompson.
+ * Copyright (c) 2002 by Lucent Technologies.
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose without fee is hereby granted, provided that this entire notice
+ * is included in all copies of any software which is or includes a copy
+ * or modification of this software and in all copies of the supporting
+ * documentation for such software.
+ * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR IMPLIED
+ * WARRANTY. IN PARTICULAR, NEITHER THE AUTHORS NOR LUCENT TECHNOLOGIES MAKE ANY
+ * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY
+ * OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE.
+ */
+
+#include "mupdf/fitz.h"
+
+#include <stdio.h>
+#include <math.h>
+#include <float.h>
+#include <string.h>
+#include <stdlib.h>
+#include <errno.h>
+
+typedef unsigned long ulong;
+
+enum { NSIGNIF	= 17 };
+
+/*
+ * first few powers of 10, enough for about 1/2 of the
+ * total space for doubles.
+ */
+static double pows10[] =
+{
+	1e0,	1e1,	1e2,	1e3,	1e4,	1e5,	1e6,	1e7,	1e8,	1e9,
+	1e10,	1e11,	1e12,	1e13,	1e14,	1e15,	1e16,	1e17,	1e18,	1e19,
+	1e20,	1e21,	1e22,	1e23,	1e24,	1e25,	1e26,	1e27,	1e28,	1e29,
+	1e30,	1e31,	1e32,	1e33,	1e34,	1e35,	1e36,	1e37,	1e38,	1e39,
+	1e40,	1e41,	1e42,	1e43,	1e44,	1e45,	1e46,	1e47,	1e48,	1e49,
+	1e50,	1e51,	1e52,	1e53,	1e54,	1e55,	1e56,	1e57,	1e58,	1e59,
+	1e60,	1e61,	1e62,	1e63,	1e64,	1e65,	1e66,	1e67,	1e68,	1e69,
+	1e70,	1e71,	1e72,	1e73,	1e74,	1e75,	1e76,	1e77,	1e78,	1e79,
+	1e80,	1e81,	1e82,	1e83,	1e84,	1e85,	1e86,	1e87,	1e88,	1e89,
+	1e90,	1e91,	1e92,	1e93,	1e94,	1e95,	1e96,	1e97,	1e98,	1e99,
+	1e100,	1e101,	1e102,	1e103,	1e104,	1e105,	1e106,	1e107,	1e108,	1e109,
+	1e110,	1e111,	1e112,	1e113,	1e114,	1e115,	1e116,	1e117,	1e118,	1e119,
+	1e120,	1e121,	1e122,	1e123,	1e124,	1e125,	1e126,	1e127,	1e128,	1e129,
+	1e130,	1e131,	1e132,	1e133,	1e134,	1e135,	1e136,	1e137,	1e138,	1e139,
+	1e140,	1e141,	1e142,	1e143,	1e144,	1e145,	1e146,	1e147,	1e148,	1e149,
+	1e150,	1e151,	1e152,	1e153,	1e154,	1e155,	1e156,	1e157,	1e158,	1e159,
+};
+#define	npows10 ((int)(sizeof(pows10)/sizeof(pows10[0])))
+#define	pow10(x) fmtpow10(x)
+
+static double
+pow10(int n)
+{
+	double d;
+	int neg;
+
+	neg = 0;
+	if(n < 0){
+		neg = 1;
+		n = -n;
+	}
+
+	if(n < npows10)
+		d = pows10[n];
+	else{
+		d = pows10[npows10-1];
+		for(;;){
+			n -= npows10 - 1;
+			if(n < npows10){
+				d *= pows10[n];
+				break;
+			}
+			d *= pows10[npows10 - 1];
+		}
+	}
+	if(neg)
+		return 1./d;
+	return d;
+}
+
+/*
+ * add 1 to the decimal integer string a of length n.
+ * if 99999 overflows into 10000, return 1 to tell caller
+ * to move the virtual decimal point.
+ */
+static int
+xadd1(char *a, int n)
+{
+	char *b;
+	int c;
+
+	if(n < 0 || n > NSIGNIF)
+		return 0;
+	for(b = a+n-1; b >= a; b--) {
+		c = *b + 1;
+		if(c <= '9') {
+			*b = c;
+			return 0;
+		}
+		*b = '0';
+	}
+	/*
+	 * need to overflow adding digit.
+	 * shift number down and insert 1 at beginning.
+	 * decimal is known to be 0s or we wouldn't
+	 * have gotten this far. (e.g., 99999+1 => 00000)
+	 */
+	a[0] = '1';
+	return 1;
+}
+
+/*
+ * subtract 1 from the decimal integer string a.
+ * if 10000 underflows into 09999, make it 99999
+ * and return 1 to tell caller to move the virtual
+ * decimal point. this way, xsub1 is inverse of xadd1.
+ */
+static int
+xsub1(char *a, int n)
+{
+	char *b;
+	int c;
+
+	if(n < 0 || n > NSIGNIF)
+		return 0;
+	for(b = a+n-1; b >= a; b--) {
+		c = *b - 1;
+		if(c >= '0') {
+			if(c == '0' && b == a) {
+				/*
+				 * just zeroed the top digit; shift everyone up.
+				 * decimal is known to be 9s or we wouldn't
+				 * have gotten this far. (e.g., 10000-1 => 09999)
+				 */
+				*b = '9';
+				return 1;
+			}
+			*b = c;
+			return 0;
+		}
+		*b = '9';
+	}
+	/*
+	 * can't get here. the number a is always normalized
+	 * so that it has a nonzero first digit.
+	 */
+	return 0;
+}
+
+/*
+ * format exponent like sprintf(p, "e%+d", e)
+ */
+static void
+fmtexp(char *p, int e)
+{
+	char se[9];
+	int i;
+
+	*p++ = 'e';
+	if(e < 0) {
+		*p++ = '-';
+		e = -e;
+	} else
+		*p++ = '+';
+	i = 0;
+	while(e) {
+		se[i++] = e % 10 + '0';
+		e /= 10;
+	}
+	while(i < 1)
+		se[i++] = '0';
+	while(i > 0)
+		*p++ = se[--i];
+	*p++ = '\0';
+}
+
+/*
+ * compute decimal integer m, exp such that:
+ *	f = m*10^exp
+ *	m is as short as possible with losing exactness
+ * assumes special cases (NaN, +Inf, -Inf) have been handled.
+ */
+void
+fz_dtoa(double f, char *s, int *exp, int *neg, int *ns)
+{
+	int c, d, e2, e, ee, i, ndigit, oerrno;
+	char tmp[NSIGNIF+10];
+	double g;
+
+	oerrno = errno; /* in case strtod smashes errno */
+
+	/*
+	 * make f non-negative.
+	 */
+	*neg = 0;
+	if(f < 0) {
+		f = -f;
+		*neg = 1;
+	}
+
+	/*
+	 * must handle zero specially.
+	 */
+	if(f == 0){
+		*exp = 0;
+		s[0] = '0';
+		s[1] = '\0';
+		*ns = 1;
+		return;
+	}
+
+	/*
+	 * find g,e such that f = g*10^e.
+	 * guess 10-exponent using 2-exponent, then fine tune.
+	 */
+	frexp(f, &e2);
+	e = (int)(e2 * .301029995664);
+	g = f * pow10(-e);
+	while(g < 1) {
+		e--;
+		g = f * pow10(-e);
+	}
+	while(g >= 10) {
+		e++;
+		g = f * pow10(-e);
+	}
+
+	/*
+	 * convert NSIGNIF digits as a first approximation.
+	 */
+	for(i=0; i<NSIGNIF; i++) {
+		d = (int)g;
+		s[i] = d+'0';
+		g = (g-d) * 10;
+	}
+	s[i] = 0;
+
+	/*
+	 * adjust e because s is 314159... not 3.14159...
+	 */
+	e -= NSIGNIF-1;
+	fmtexp(s+NSIGNIF, e);
+
+	/*
+	 * adjust conversion until strtod(s) == f exactly.
+	 */
+	for(i=0; i<10; i++) {
+		g = fz_strtod(s, NULL);
+		if(f > g) {
+			if(xadd1(s, NSIGNIF)) {
+				/* gained a digit */
+				e--;
+				fmtexp(s+NSIGNIF, e);
+			}
+			continue;
+		}
+		if(f < g) {
+			if(xsub1(s, NSIGNIF)) {
+				/* lost a digit */
+				e++;
+				fmtexp(s+NSIGNIF, e);
+			}
+			continue;
+		}
+		break;
+	}
+
+	/*
+	 * play with the decimal to try to simplify.
+	 */
+
+	/*
+	 * bump last few digits up to 9 if we can
+	 */
+	for(i=NSIGNIF-1; i>=NSIGNIF-3; i--) {
+		c = s[i];
+		if(c != '9') {
+			s[i] = '9';
+			g = fz_strtod(s, NULL);
+			if(g != f) {
+				s[i] = c;
+				break;
+			}
+		}
+	}
+
+	/*
+	 * add 1 in hopes of turning 9s to 0s
+	 */
+	if(s[NSIGNIF-1] == '9') {
+		strcpy(tmp, s);
+		ee = e;
+		if(xadd1(tmp, NSIGNIF)) {
+			ee--;
+			fmtexp(tmp+NSIGNIF, ee);
+		}
+		g = fz_strtod(tmp, NULL);
+		if(g == f) {
+			strcpy(s, tmp);
+			e = ee;
+		}
+	}
+
+	/*
+	 * bump last few digits down to 0 as we can.
+	 */
+	for(i=NSIGNIF-1; i>=NSIGNIF-3; i--) {
+		c = s[i];
+		if(c != '0') {
+			s[i] = '0';
+			g = fz_strtod(s, NULL);
+			if(g != f) {
+				s[i] = c;
+				break;
+			}
+		}
+	}
+
+	/*
+	 * remove trailing zeros.
+	 */
+	ndigit = NSIGNIF;
+	while(ndigit > 1 && s[ndigit-1] == '0'){
+		e++;
+		--ndigit;
+	}
+	s[ndigit] = 0;
+	*exp = e;
+	*ns = ndigit;
+	errno = oerrno;
+}
+
+static ulong
+umuldiv(ulong a, ulong b, ulong c)
+{
+	double d;
+
+	d = ((double)a * (double)b) / (double)c;
+	if(d >= 4294967295.)
+		d = 4294967295.;
+	return (ulong)d;
+}
+
+/*
+ * This routine will convert to arbitrary precision
+ * floating point entirely in multi-precision fixed.
+ * The answer is the closest floating point number to
+ * the given decimal number. Exactly half way are
+ * rounded ala ieee rules.
+ * Method is to scale input decimal between .500 and .999...
+ * with external power of 2, then binary search for the
+ * closest mantissa to this decimal number.
+ * Nmant is is the required precision. (53 for ieee dp)
+ * Nbits is the max number of bits/word. (must be <= 28)
+ * Prec is calculated - the number of words of fixed mantissa.
+ */
+enum
+{
+	Nbits	= 28,				/* bits safely represented in a ulong */
+	Nmant	= 53,				/* bits of precision required */
+	Prec	= (Nmant+Nbits+1)/Nbits,	/* words of Nbits each to represent mantissa */
+	Sigbit	= 1<<(Prec*Nbits-Nmant),	/* first significant bit of Prec-th word */
+	Ndig	= 1500,
+	One	= (ulong)(1<<Nbits),
+	Half	= (ulong)(One>>1),
+	Maxe	= 310,
+
+	Fsign	= 1<<0,		/* found - */
+	Fesign	= 1<<1,		/* found e- */
+	Fdpoint	= 1<<2,		/* found . */
+
+	S0	= 0,		/* _		_S0	+S1	#S2	.S3 */
+	S1,			/* _+		#S2	.S3 */
+	S2,			/* _+#		#S2	.S4	eS5 */
+	S3,			/* _+.		#S4 */
+	S4,			/* _+#.#	#S4	eS5 */
+	S5,			/* _+#.#e	+S6	#S7 */
+	S6,			/* _+#.#e+	#S7 */
+	S7			/* _+#.#e+#	#S7 */
+};
+
+static	int	xcmp(char*, char*);
+static	int	fpcmp(char*, ulong*);
+static	void	frnorm(ulong*);
+static	void	divascii(char*, int*, int*, int*);
+static	void	mulascii(char*, int*, int*, int*);
+
+typedef	struct	Tab	Tab;
+struct	Tab
+{
+	int	bp;
+	int	siz;
+	char*	cmp;
+};
+
+double
+fz_strtod(const char *as, char **aas)
+{
+	int na, ex, dp, bp, c, i, flag, state;
+	ulong low[Prec], hig[Prec], mid[Prec];
+	double d;
+	char *s, a[Ndig];
+
+	flag = 0;	/* Fsign, Fesign, Fdpoint */
+	na = 0;		/* number of digits of a[] */
+	dp = 0;		/* na of decimal point */
+	ex = 0;		/* exonent */
+
+	state = S0;
+	for(s=(char*)as;; s++) {
+		c = *s;
+		if(c >= '0' && c <= '9') {
+			switch(state) {
+			case S0:
+			case S1:
+			case S2:
+				state = S2;
+				break;
+			case S3:
+			case S4:
+				state = S4;
+				break;
+
+			case S5:
+			case S6:
+			case S7:
+				state = S7;
+				ex = ex*10 + (c-'0');
+				continue;
+			}
+			if(na == 0 && c == '0') {
+				dp--;
+				continue;
+			}
+			if(na < Ndig-50)
+				a[na++] = c;
+			continue;
+		}
+		switch(c) {
+		case '\t':
+		case '\n':
+		case '\v':
+		case '\f':
+		case '\r':
+		case ' ':
+			if(state == S0)
+				continue;
+			break;
+		case '-':
+			if(state == S0)
+				flag |= Fsign;
+			else
+				flag |= Fesign;
+		case '+':
+			if(state == S0)
+				state = S1;
+			else
+			if(state == S5)
+				state = S6;
+			else
+				break;	/* syntax */
+			continue;
+		case '.':
+			flag |= Fdpoint;
+			dp = na;
+			if(state == S0 || state == S1) {
+				state = S3;
+				continue;
+			}
+			if(state == S2) {
+				state = S4;
+				continue;
+			}
+			break;
+		case 'e':
+		case 'E':
+			if(state == S2 || state == S4) {
+				state = S5;
+				continue;
+			}
+			break;
+		}
+		break;
+	}
+
+	/*
+	 * clean up return char-pointer
+	 */
+	switch(state) {
+	case S0:
+		if(xcmp(s, "nan") == 0) {
+			if(aas != NULL)
+				*aas = s+3;
+			goto retnan;
+		}
+	case S1:
+		if(xcmp(s, "infinity") == 0) {
+			if(aas != NULL)
+				*aas = s+8;
+			goto retinf;
+		}
+		if(xcmp(s, "inf") == 0) {
+			if(aas != NULL)
+				*aas = s+3;
+			goto retinf;
+		}
+	case S3:
+		if(aas != NULL)
+			*aas = (char*)as;
+		goto ret0;	/* no digits found */
+	case S6:
+		s--;		/* back over +- */
+	case S5:
+		s--;		/* back over e */
+		break;
+	}
+	if(aas != NULL)
+		*aas = s;
+
+	if(flag & Fdpoint)
+	while(na > 0 && a[na-1] == '0')
+		na--;
+	if(na == 0)
+		goto ret0;	/* zero */
+	a[na] = 0;
+	if(!(flag & Fdpoint))
+		dp = na;
+	if(flag & Fesign)
+		ex = -ex;
+	dp += ex;
+	if(dp < -Maxe){
+		errno = ERANGE;
+		goto ret0;	/* underflow by exp */
+	} else
+	if(dp > +Maxe)
+		goto retinf;	/* overflow by exp */
+
+	/*
+	 * normalize the decimal ascii number
+	 * to range .[5-9][0-9]* e0
+	 */
+	bp = 0;		/* binary exponent */
+	while(dp > 0)
+		divascii(a, &na, &dp, &bp);
+	while(dp < 0 || a[0] < '5')
+		mulascii(a, &na, &dp, &bp);
+
+	/* close approx by naive conversion */
+	mid[0] = 0;
+	mid[1] = 1;
+	for(i=0; (c=a[i]) != '\0'; i++) {
+		mid[0] = mid[0]*10 + (c-'0');
+		mid[1] = mid[1]*10;
+		if(i >= 8)
+			break;
+	}
+	low[0] = umuldiv(mid[0], One, mid[1]);
+	hig[0] = umuldiv(mid[0]+1, One, mid[1]);
+	for(i=1; i<Prec; i++) {
+		low[i] = 0;
+		hig[i] = One-1;
+	}
+
+	/* binary search for closest mantissa */
+	for(;;) {
+		/* mid = (hig + low) / 2 */
+		c = 0;
+		for(i=0; i<Prec; i++) {
+			mid[i] = hig[i] + low[i];
+			if(c)
+				mid[i] += One;
+			c = mid[i] & 1;
+			mid[i] >>= 1;
+		}
+		frnorm(mid);
+
+		/* compare */
+		c = fpcmp(a, mid);
+		if(c > 0) {
+			c = 1;
+			for(i=0; i<Prec; i++)
+				if(low[i] != mid[i]) {
+					c = 0;
+					low[i] = mid[i];
+				}
+			if(c)
+				break;	/* between mid and hig */
+			continue;
+		}
+		if(c < 0) {
+			for(i=0; i<Prec; i++)
+				hig[i] = mid[i];
+			continue;
+		}
+
+		/* only hard part is if even/odd roundings wants to go up */
+		c = mid[Prec-1] & (Sigbit-1);
+		if(c == Sigbit/2 && (mid[Prec-1]&Sigbit) == 0)
+			mid[Prec-1] -= c;
+		break;	/* exactly mid */
+	}
+
+	/* normal rounding applies */
+	c = mid[Prec-1] & (Sigbit-1);
+	mid[Prec-1] -= c;
+	if(c >= Sigbit/2) {
+		mid[Prec-1] += Sigbit;
+		frnorm(mid);
+	}
+	goto out;
+
+ret0:
+	return 0;
+
+retnan:
+	return NAN;
+
+retinf:
+	/*
+	 * Unix strtod requires these. Plan 9 would return Inf(0) or Inf(-1). */
+	errno = ERANGE;
+	if(flag & Fsign)
+		return -HUGE_VAL;
+	return HUGE_VAL;
+
+out:
+	d = 0;
+	for(i=0; i<Prec; i++)
+		d = d*One + mid[i];
+	if(flag & Fsign)
+		d = -d;
+	d = ldexp(d, bp - Prec*Nbits);
+	if(d == 0){	/* underflow */
+		errno = ERANGE;
+	}
+	return d;
+}
+
+static void
+frnorm(ulong *f)
+{
+	int i, c;
+
+	c = 0;
+	for(i=Prec-1; i>0; i--) {
+		f[i] += c;
+		c = f[i] >> Nbits;
+		f[i] &= One-1;
+	}
+	f[0] += c;
+}
+
+static int
+fpcmp(char *a, ulong* f)
+{
+	ulong tf[Prec];
+	int i, d, c;
+
+	for(i=0; i<Prec; i++)
+		tf[i] = f[i];
+
+	for(;;) {
+		/* tf *= 10 */
+		for(i=0; i<Prec; i++)
+			tf[i] = tf[i]*10;
+		frnorm(tf);
+		d = (tf[0] >> Nbits) + '0';
+		tf[0] &= One-1;
+
+		/* compare next digit */
+		c = *a;
+		if(c == 0) {
+			if('0' < d)
+				return -1;
+			if(tf[0] != 0)
+				goto cont;
+			for(i=1; i<Prec; i++)
+				if(tf[i] != 0)
+					goto cont;
+			return 0;
+		}
+		if(c > d)
+			return +1;
+		if(c < d)
+			return -1;
+		a++;
+	cont:;
+	}
+}
+
+static void
+divby(char *a, int *na, int b)
+{
+	int n, c;
+	char *p;
+
+	p = a;
+	n = 0;
+	while(n>>b == 0) {
+		c = *a++;
+		if(c == 0) {
+			while(n) {
+				c = n*10;
+				if(c>>b)
+					break;
+				n = c;
+			}
+			goto xx;
+		}
+		n = n*10 + c-'0';
+		(*na)--;
+	}
+	for(;;) {
+		c = n>>b;
+		n -= c<<b;
+		*p++ = c + '0';
+		c = *a++;
+		if(c == 0)
+			break;
+		n = n*10 + c-'0';
+	}
+	(*na)++;
+xx:
+	while(n) {
+		n = n*10;
+		c = n>>b;
+		n -= c<<b;
+		*p++ = c + '0';
+		(*na)++;
+	}
+	*p = 0;
+}
+
+static	Tab	tab1[] =
+{
+	{ 1, 0, "" },
+	{ 3, 1, "7" },
+	{ 6, 2, "63" },
+	{ 9, 3, "511" },
+	{ 13, 4, "8191" },
+	{ 16, 5, "65535" },
+	{ 19, 6, "524287" },
+	{ 23, 7, "8388607" },
+	{ 26, 8, "67108863" },
+	{ 27, 9, "134217727" },
+};
+
+static void
+divascii(char *a, int *na, int *dp, int *bp)
+{
+	int b, d;
+	Tab *t;
+
+	d = *dp;
+	if(d >= (int)(nelem(tab1)))
+		d = (int)(nelem(tab1))-1;
+	t = tab1 + d;
+	b = t->bp;
+	if(memcmp(a, t->cmp, t->siz) > 0)
+		d--;
+	*dp -= d;
+	*bp += b;
+	divby(a, na, b);
+}
+
+static void
+mulby(char *a, char *p, char *q, int b)
+{
+	int n, c;
+
+	n = 0;
+	*p = 0;
+	for(;;) {
+		q--;
+		if(q < a)
+			break;
+		c = *q - '0';
+		c = (c<<b) + n;
+		n = c/10;
+		c -= n*10;
+		p--;
+		*p = c + '0';
+	}
+	while(n) {
+		c = n;
+		n = c/10;
+		c -= n*10;
+		p--;
+		*p = c + '0';
+	}
+}
+
+static	Tab	tab2[] =
+{
+	{ 1, 1, "" },				/* dp = 0-0 */
+	{ 3, 3, "125" },
+	{ 6, 5, "15625" },
+	{ 9, 7, "1953125" },
+	{ 13, 10, "1220703125" },
+	{ 16, 12, "152587890625" },
+	{ 19, 14, "19073486328125" },
+	{ 23, 17, "11920928955078125" },
+	{ 26, 19, "1490116119384765625" },
+	{ 27, 19, "7450580596923828125" },		/* dp 8-9 */
+};
+
+static void
+mulascii(char *a, int *na, int *dp, int *bp)
+{
+	char *p;
+	int d, b;
+	Tab *t;
+
+	d = -*dp;
+	if(d >= (int)(nelem(tab2)))
+		d = (int)(nelem(tab2))-1;
+	t = tab2 + d;
+	b = t->bp;
+	if(memcmp(a, t->cmp, t->siz) < 0)
+		d--;
+	p = a + *na;
+	*bp -= b;
+	*dp += d;
+	*na += d;
+	mulby(a, p+d, p, b);
+}
+
+static int
+xcmp(char *a, char *b)
+{
+	int c1, c2;
+
+	while((c1 = *b++) != '\0') {
+		c2 = *a++;
+		if(c2 >= 'A' && c2 <= 'Z')
+			c2 = c2 - 'A' + 'a';
+		if(c1 != c2)
+			return 1;
+	}
+	return 0;
+}
diff --git a/source/fitz/printf.c b/source/fitz/printf.c
index e9d43dbb..b4fe844a 100644
--- a/source/fitz/printf.c
+++ b/source/fitz/printf.c
@@ -15,44 +15,6 @@ static void fmtputc(struct fmtbuf *out, int c)
 }
 
 /*
- * Compute decimal integer m, exp such that:
- *	f = m*10^exp
- *	m is as short as possible with losing exactness
- * assumes special cases (NaN, +Inf, -Inf) have been handled.
- */
-static void fz_dtoa(float f, char *digits, int *exp, int *neg, int *ndigits)
-{
-	char buf[20], *s, *p, *e;
-	int n;
-
-	/* TODO: binary search */
-	for (n = 1; n < 9; ++n) {
-		sprintf(buf, "%+.*e", n, f);
-		if (strtof(buf, NULL) == f)
-			break;
-	}
-
-	*neg = (buf[0] == '-');
-
-	p = buf + 3;
-	e = strchr(p, 'e');
-	*exp = atoi(e + 1) - (e - p);
-
-	if (e[-1] == '0') {
-		--e;
-		++(*exp);
-	}
-
-	s = digits;
-	*s++ = buf[1];
-	while (p < e)
-		*s++ = *p++;
-	*s = 0;
-
-	*ndigits = s - digits;
-}
-
-/*
  * Convert float to shortest possible string that won't lose precision, except:
  * NaN to 0, +Inf to FLT_MAX, -Inf to -FLT_MAX.
  */
diff --git a/source/fitz/string.c b/source/fitz/string.c
index 1442b205..cab8387e 100644
--- a/source/fitz/string.c
+++ b/source/fitz/string.c
@@ -247,7 +247,7 @@ float fz_atof(const char *s)
 	 * don't read a number that's OK as a double and then become invalid
 	 * as we convert to a float. */
 	errno = 0;
-	d = strtod(s, NULL);
+	d = fz_strtod(s, NULL);
 	if (errno == ERANGE || isnan(d)) {
 		/* Return 1.0, as it's a small known value that won't cause a divide by 0. */
 		return 1.0;
diff --git a/source/xps/xps-path.c b/source/xps/xps-path.c
index 7b71575f..cf4f2ff7 100644
--- a/source/xps/xps-path.c
+++ b/source/xps/xps-path.c
@@ -12,7 +12,7 @@ xps_parse_float_array(char *s, int num, float *x)
 	{
 		while (*s == 0x0d || *s == '\t' || *s == ' ' || *s == 0x0a)
 			s++;
-		x[k] = (float)strtod(s, &s);
+		x[k] = (float)fz_strtod(s, &s);
 		while (*s == 0x0d || *s == '\t' || *s == ' ' || *s == 0x0a)
 			s++;
 		if (*s == ',')