Fixed bug #42785 (json_encode() formats doubles according to locale rather
then following standard syntax).

Author: Ilia Alshanetsky

ext/json/json.c

@@ -359,7 +359,7 @@ static void json_encode_r(smart_str *buf, zval *val TSRMLS_DC) /* {{{ */
                 double dbl = Z_DVAL_P(val);
 
                 if (!zend_isinf(dbl) && !zend_isnan(dbl)) {
-			len = spprintf(&d, 0, "%.*g", (int) EG(precision), dbl);
+			len = spprintf(&d, 0, "%.*k", (int) EG(precision), dbl);
 			smart_str_appendl(buf, d, len);
 			efree(d);
                 } else {

main/snprintf.c

@@ -1004,6 +1004,7 @@ static int format_converter(register buffy * odp, const char *fmt, va_list ap) /
 
 
 				case 'g':
+				case 'k':
 				case 'G':
 				case 'H':
 					switch(modifier) {
@@ -1045,7 +1046,7 @@ static int format_converter(register buffy * odp, const char *fmt, va_list ap) /
 						lconv = localeconv();
 					}
 #endif
-					s = php_gcvt(fp_num, precision, *fmt=='H' ? '.' : LCONV_DECIMAL_POINT, (*fmt == 'G' || *fmt == 'H')?'E':'e', &num_buf[1]);
+					s = php_gcvt(fp_num, precision, (*fmt=='H' || *fmt == 'k') ? '.' : LCONV_DECIMAL_POINT, (*fmt == 'G' || *fmt == 'H')?'E':'e', &num_buf[1]);
 					if (*s == '-') {
 						prefix_char = *s++;
 					} else if (print_sign) {

main/spprintf.c

@@ -600,6 +600,7 @@ static void xbuf_format_converter(smart_str *xbuf, const char *fmt, va_list ap)
 
 
 				case 'g':
+				case 'k':
 				case 'G':
 				case 'H':
 					switch(modifier) {
@@ -640,7 +641,7 @@ static void xbuf_format_converter(smart_str *xbuf, const char *fmt, va_list ap)
 						lconv = localeconv();
 					}
 #endif
-					s = php_gcvt(fp_num, precision, *fmt=='H' ? '.' : LCONV_DECIMAL_POINT, (*fmt == 'G' || *fmt == 'H')?'E':'e', &num_buf[1]);
+					s = php_gcvt(fp_num, precision, (*fmt=='H' || *fmt == 'k') ? '.' : LCONV_DECIMAL_POINT, (*fmt == 'G' || *fmt == 'H')?'E':'e', &num_buf[1]);
 					if (*s == '-')
 						prefix_char = *s++;
 					else if (print_sign)