grin v5.3 (0124) Fix leading zeroes bugs (mimblewimble#3763)

* remove two unneeded mut's
* ensure correct size for leading_zeros()

Author: bayk

core/src/pow/cuckaroo.rs

@@ -65,8 +65,8 @@ impl PoWContext for CuckarooContext {
 		let mut uvs = vec![0u64; 2 * size];
 		let mut xor0: u64 = 0;
 		let mut xor1: u64 = 0;
-		let mask = u64::MAX >> size.leading_zeros(); // round size up to 2-power - 1
-											 // the next three arrays form a linked list of nodes with matching bits 6..1
+		let mask = u64::MAX >> (size as u64).leading_zeros(); // round size up to 2-power - 1
+													  // the next three arrays form a linked list of nodes with matching bits 6..1
 		let mut headu = vec![2 * size; 1 + mask as usize];
 		let mut headv = vec![2 * size; 1 + mask as usize];
 		let mut prev = vec![0usize; 2 * size];

core/src/pow/cuckarood.rs

@@ -65,8 +65,8 @@ impl PoWContext for CuckaroodContext {
 		let mut ndir = vec![0usize; 2];
 		let mut xor0: u64 = 0;
 		let mut xor1: u64 = 0;
-		let mask = u64::MAX >> size.leading_zeros(); // round size up to 2-power - 1
-											 // the next two arrays form a linked list of nodes with matching bits 4..0|dir
+		let mask = u64::MAX >> (size as u64).leading_zeros(); // round size up to 2-power - 1
+													  // the next two arrays form a linked list of nodes with matching bits 4..0|dir
 		let mut headu = vec![2 * size; 1 + mask as usize];
 		let mut headv = vec![2 * size; 1 + mask as usize];
 		let mut prev = vec![0usize; 2 * size];

core/src/pow/cuckaroom.rs

@@ -64,8 +64,8 @@ impl PoWContext for CuckaroomContext {
 		let mut to = vec![0u64; size];
 		let mut xor_from: u64 = 0;
 		let mut xor_to: u64 = 0;
-		let mask = u64::MAX >> size.leading_zeros(); // round size up to 2-power - 1
-											 // the next two arrays form a linked list of nodes with matching bits 6..1
+		let mask = u64::MAX >> (size as u64).leading_zeros(); // round size up to 2-power - 1
+													  // the next two arrays form a linked list of nodes with matching bits 6..1
 		let mut head = vec![size; 1 + mask as usize];
 		let mut prev = vec![0usize; size];
 

core/src/pow/cuckarooz.rs

@@ -63,8 +63,8 @@ impl PoWContext for CuckaroozContext {
 		let nonces = &proof.nonces;
 		let mut uvs = vec![0u64; 2 * size];
 		let mut xoruv: u64 = 0;
-		let mask = u64::MAX >> size.leading_zeros(); // round size up to 2-power - 1
-											 // the next two arrays form a linked list of nodes with matching bits 6..1
+		let mask = u64::MAX >> (size as u64).leading_zeros(); // round size up to 2-power - 1
+													  // the next two arrays form a linked list of nodes with matching bits 6..1
 		let mut head = vec![2 * size; 1 + mask as usize];
 		let mut prev = vec![0usize; 2 * size];
 

core/src/pow/cuckatoo.rs

@@ -261,7 +261,7 @@ impl CuckatooContext {
 		}
 		let nonces = &proof.nonces;
 		let mut uvs = vec![0u64; 2 * size];
-		let mask = u64::MAX >> size.leading_zeros(); // round size up to 2-power - 1
+		let mask = u64::MAX >> (size as u64).leading_zeros(); // round size up to 2-power - 1
 		let mut xor0: u64 = (size as u64 / 2) & 1;
 		let mut xor1: u64 = xor0;
 		// the next two arrays form a linked list of nodes with matching bits 6..1