From 66868abc75df7367298c8973aed1580f7d05703a Mon Sep 17 00:00:00 2001
From: Sutou Kouhei <kou@cozmixng.org>
Date: Thu, 10 Oct 2024 17:02:47 +0900
Subject: [PATCH] Accept no digits in the fractional part (#302)

fix #301

For example, "0.E-9" and "0." are accepted.

FYI:

`Float()`/`.to_f` will accept "0.E-9":
https://bugs.ruby-lang.org/issues/20705

The current `Float` doesn't accept "0." but `.to_f` accepts "0.".
---
 ext/bigdecimal/bigdecimal.c        | 9 ++-------
 test/bigdecimal/test_bigdecimal.rb | 2 ++
 2 files changed, 4 insertions(+), 7 deletions(-)

diff --git a/ext/bigdecimal/bigdecimal.c b/ext/bigdecimal/bigdecimal.c
index 6d48741..34dae9f 100644
--- a/ext/bigdecimal/bigdecimal.c
+++ b/ext/bigdecimal/bigdecimal.c
@@ -5277,7 +5277,7 @@ VP_EXPORT Real *
 VpAlloc(size_t mx, const char *szVal, int strict_p, int exc)
 {
     const char *orig_szVal = szVal;
-    size_t i, j, ni, ipf, nf, ipe, ne, dot_seen, exp_seen, nalloc;
+    size_t i, j, ni, ipf, nf, ipe, ne, exp_seen, nalloc;
     size_t len;
     char v, *psz;
     int  sign=1;
@@ -5363,13 +5363,11 @@ VpAlloc(size_t mx, const char *szVal, int strict_p, int exc)
     ne  = 0; /* number of digits in the exponential part */
     ipf = 0; /* index of the beginning of the fractional part */
     ipe = 0; /* index of the beginning of the exponential part */
-    dot_seen = 0;
     exp_seen = 0;
 
     if (v != '\0') {
         /* Scanning fractional part */
         if ((psz[i] = szVal[j]) == '.') {
-            dot_seen = 1;
             ++i;
             ++j;
             ipf = i;
@@ -5385,9 +5383,6 @@ VpAlloc(size_t mx, const char *szVal, int strict_p, int exc)
                     }
                     if (!strict_p) {
                         v = psz[i] = '\0';
-                        if (nf == 0) {
-                            dot_seen = 0;
-                        }
                         break;
                     }
                     goto invalid_value;
@@ -5458,7 +5453,7 @@ VpAlloc(size_t mx, const char *szVal, int strict_p, int exc)
 
     psz[i] = '\0';
 
-    if (strict_p && (((ni == 0 || dot_seen) && nf == 0) || (exp_seen && ne == 0))) {
+    if (strict_p && ((ni == 0 && nf == 0) || (exp_seen && ne == 0))) {
         VALUE str;
       invalid_value:
         if (!strict_p) {
diff --git a/test/bigdecimal/test_bigdecimal.rb b/test/bigdecimal/test_bigdecimal.rb
index cae3375..dbc00e5 100644
--- a/test/bigdecimal/test_bigdecimal.rb
+++ b/test/bigdecimal/test_bigdecimal.rb
@@ -74,6 +74,8 @@ def test_BigDecimal
     assert_equal(111, BigDecimal("1_1_1_"))
     assert_equal(10**(-1), BigDecimal("1E-1"), '#4825')
     assert_equal(1234, BigDecimal(" \t\n\r \r1234 \t\n\r \r"))
+    assert_equal(0.0, BigDecimal("0."))
+    assert_equal(0.0E-9, BigDecimal("0.E-9"))
 
     assert_raise(ArgumentError) { BigDecimal("1", -1) }
     assert_raise_with_message(ArgumentError, /"1__1_1"/) { BigDecimal("1__1_1") }