2 files changed, 14 insertions, 14 deletions
diff --git a/ext/json/generator/generator.c b/ext/json/generator/generator.c
index 8fcc980d47..9b67629f96 100644
--- a/ext/json/generator/generator.c
+++ b/ext/json/generator/generator.c
@@ -1345,12 +1345,11 @@ static void generate_json_float(FBuffer *buffer, struct generate_json_data *data
     }
 
     /* This implementation writes directly into the buffer. We reserve
-     * the 28 characters that fpconv_dtoa states as its maximum.
+     * the 32 characters that fpconv_dtoa states as its maximum.
      */
-    fbuffer_inc_capa(buffer, 28);
+    fbuffer_inc_capa(buffer, 32);
     char* d = buffer->ptr + buffer->len;
     int len = fpconv_dtoa(value, d);
-
     /* fpconv_dtoa converts a float to its shortest string representation,
      * but it adds a ".0" if this is a plain integer.
      */
diff --git a/ext/json/vendor/fpconv.c b/ext/json/vendor/fpconv.c
index 75efd46f11..e91c7889c2 100644
--- a/ext/json/vendor/fpconv.c
+++ b/ext/json/vendor/fpconv.c
@@ -29,6 +29,10 @@
 #include <string.h>
 #include <stdint.h>
 
+#ifdef JSON_DEBUG
+#include <assert.h>
+#endif
+
 #define npowers     87
 #define steppowers  8
 #define firstpower -348 /* 10 ^ -348 */
@@ -320,15 +324,7 @@ static int emit_digits(char* digits, int ndigits, char* dest, int K, bool neg)
 {
     int exp = absv(K + ndigits - 1);
 
-    int max_trailing_zeros = 7;
-
-    if(neg) {
-        max_trailing_zeros -= 1;
-    }
-
-    /* write plain integer */
-    if(K >= 0 && (exp < (ndigits + max_trailing_zeros))) {
-
+    if(K >= 0 && exp < 15) {
         memcpy(dest, digits, ndigits);
         memset(dest + ndigits, '0', K);
 
@@ -432,10 +428,12 @@ static int filter_special(double fp, char* dest)
  *
  * Input:
  * fp -> the double to convert, dest -> destination buffer.
- * The generated string will never be longer than 28 characters.
- * Make sure to pass a pointer to at least 28 bytes of memory.
+ * The generated string will never be longer than 32 characters.
+ * Make sure to pass a pointer to at least 32 bytes of memory.
  * The emitted string will not be null terminated.
  *
+ *
+ *
  * Output:
  * The number of written characters.
  *
@@ -474,6 +472,9 @@ static int fpconv_dtoa(double d, char dest[28])
     int ndigits = grisu2(d, digits, &K);
 
     str_len += emit_digits(digits, ndigits, dest + str_len, K, neg);
+#ifdef JSON_DEBUG
+    assert(str_len <= 32);
+#endif
 
     return str_len;
 }