Fix VariantWriter overflow on 64-bit int

Integers in Godot are signed 64-bit ints (int64_t), but var2str used
int behind the scenes and would thus overflow after 2^31.

Also properly documented the actual bounds of int and the behaviour
when overflowing them.

1 files changed, 15 insertions, 1 deletions

diff --git a/doc/classes/int.xml b/doc/classes/int.xml
index 4855fa2848..7175b9fd88 100644
--- a/doc/classes/int.xml
+++ b/doc/classes/int.xml
@@ -4,7 +4,21 @@
 		Integer built-in type.
 	</brief_description>
 	<description>
-		Integer built-in type.
+		Signed 64-bit integer type.
+		It can take values in the interval [code][-2^63, 2^63 - 1][/code], i.e. [code][-9223372036854775808, 9223372036854775807][/code]. Exceeding those bounds will wrap around.
+		[code]int[/code] is a [Variant] type, and will thus be used when assigning an integer value to a [Variant]. It can also be enforced with the [code]: int[/code] type hint.
+		[codeblock]
+		var my_variant = 0    # int, value 0
+		my_variant += 4.2     # float, value 4.2
+		var my_int: int = 1   # int, value 1
+		my_int = 4.2          # int, value 4, the right value is implicitly cast to int
+		my_int = int("6.7")   # int, value 6, the String is explicitly cast with [method int]
+
+		var max_int = 9223372036854775807
+		print(max_int)        # 9223372036854775807, OK
+		max_int += 1
+		print(max_int)        # -9223372036854775808, we overflowed and wrapped around
+		[/codeblock]
 	</description>
 	<tutorials>
 	</tutorials>