Avoid RangeError on integers larger than LONG_LONG

Author: nurse

ext/mysql2/extconf.rb

@@ -12,6 +12,9 @@ def asplode(lib)
   end
 end
 
+# 2.1+
+have_func('rb_absint_size')
+
 # 2.0-only
 have_header('ruby/thread.h') && have_func('rb_thread_call_without_gvl', 'ruby/thread.h')
 

ext/mysql2/statement.c

@@ -204,6 +204,32 @@ static void set_buffer_for_string(MYSQL_BIND* bind_buffer, unsigned long *length
     xfree(length_buffers);                                  \
   }
 
+/* return 0 if the given bignum can cast as LONG_LONG, otherwise 1 */
+int my_big2ll(VALUE bignum, LONG_LONG *ptr)
+{
+    unsigned LONG_LONG num;
+#ifdef HAVE_RB_ABSINT_SIZE
+    if (rb_absint_size(bignum, NULL) > 8) goto overflow;
+#else
+    if (RBIGNUM_LEN(bignum)*SIZEOF_BDIGITS > 8) goto overflow;
+#endif
+    if (RBIGNUM_POSITIVE_P(bignum)) {
+        num = rb_big2ull(bignum);
+        if (num > LLONG_MAX)
+            goto overflow;
+        *ptr = num;
+    }
+    else {
+        if (rb_big_cmp(bignum, LL2NUM(LLONG_MIN)) == INT2FIX(-1))
+            goto overflow;
+        *ptr = rb_big2ll(bignum);
+    }
+    return 0;
+overflow:
+    *ptr = -1; /* TODO */
+    return 1;
+}
+
 /* call-seq: stmt.execute
  *
  * Executes the current prepared statement, returns +result+.
@@ -267,7 +293,7 @@ static VALUE execute(int argc, VALUE *argv, VALUE self) {
         case T_BIGNUM:
           bind_buffers[i].buffer_type = MYSQL_TYPE_LONGLONG;
           bind_buffers[i].buffer = xmalloc(sizeof(long long int));
-          *(LONG_LONG*)(bind_buffers[i].buffer) = rb_big2ll(argv[i]);
+          my_big2ll(argv[i], (LONG_LONG*)(bind_buffers[i].buffer));
           break;
         case T_FLOAT:
           bind_buffers[i].buffer_type = MYSQL_TYPE_DOUBLE;

spec/mysql2/statement_spec.rb

@@ -59,6 +59,24 @@
     expect(rows).to eq([{ "1" => 1 }])
   end
 
+  it "should handle bignum but in int64_t" do
+    stmt = @client.prepare('SELECT ? AS max, ? AS min')
+    int64_max = (1 << 63)-1
+    int64_min = -(1 << 63)
+    result = stmt.execute(int64_max, int64_min)
+    expect(result.to_a).to eq(['max' => int64_max, 'min' => int64_min])
+    @client.query 'DROP TABLE IF EXISTS mysql2_stmt_q'
+  end
+
+  it "should handle bignum but beyond int64_t" do
+    stmt = @client.prepare('SELECT ? AS max1, ? AS min1')
+    int64_max1 = (1 << 63)
+    int64_min1 = -(1 << 63)-2
+    result = stmt.execute(int64_max1, int64_min1)
+    expect(result.to_a).to eq(['max1' => -1, 'min1' => -1])
+    @client.query 'DROP TABLE IF EXISTS mysql2_stmt_q'
+  end
+
   it "should keep its result after other query" do
     @client.query 'USE test'
     @client.query 'CREATE TABLE IF NOT EXISTS mysql2_stmt_q(a int)'