Fixed edge cases of nearest_po2 function

core/variant/variant_utility.cpp

@@ -641,7 +641,17 @@ struct VariantUtilityFunctions {
 	}
 
 	static inline int64_t nearest_po2(int64_t x) {
-		return nearest_power_of_2_templated(uint64_t(x));
+		if (x <= 1) {
+			return 1;
+		}
+		--x;
+		x |= x >> 1;
+		x |= x >> 2;
+		x |= x >> 4;
+		x |= x >> 8;
+		x |= x >> 16;
+		x |= x >> 32;
+		return ++x;
 	}
 
 	// Random

doc/classes/@GlobalScope.xml

@@ -692,17 +692,14 @@
 			<return type="int" />
 			<param index="0" name="value" type="int" />
 			<description>
-				Returns the nearest equal or larger power of 2 for the integer [param value].
+				Returns the smallest power of 2 that is equal to or larger than [param value].
 				In other words, returns the smallest value [code]a[/code] where [code]a = pow(2, n)[/code] such that [code]value &lt;= a[/code] for some non-negative integer [code]n[/code].
 				[codeblock]
 				nearest_po2(3) # Returns 4
 				nearest_po2(4) # Returns 4
 				nearest_po2(5) # Returns 8
-
-				nearest_po2(0)  # Returns 0 (this may not be expected)
-				nearest_po2(-1) # Returns 0 (this may not be expected)
+				nearest_po2(0) # Returns 1
 				[/codeblock]
-				[b]Warning:[/b] Due to the way it is implemented, this function returns [code]0[/code] rather than [code]1[/code] for negative values of [param value] (in reality, 1 is the smallest integer power of 2).
 			</description>
 		</method>
 		<method name="pingpong">

modules/mono/glue/GodotSharp/GodotSharp/Core/Mathf.cs

@@ -625,6 +625,9 @@ public static real_t MoveToward(real_t from, real_t to, real_t delta)
         /// <returns>The nearest larger power of 2.</returns>
         public static int NearestPo2(int value)
         {
+            if (value <= 1)
+			       return 1;
+
             value--;
             value |= value >> 1;
             value |= value >> 2;