Fix chain GetByHeight() to prevent potential crash on a returned nil pointer

stringintech · stringintech · commit 2279f705bf90 · 2025-09-24T13:52:03.000+03:30
This was missed when adapting to kernelApi_65
diff --git a/kernel/chain.go b/kernel/chain.go
@@ -29,12 +29,11 @@ func (c *Chain) GetGenesis() *BlockTreeEntry {
 
 // GetByHeight returns the block tree entry for the given height in the chain, or nil if it does not exist
 func (c *Chain) GetByHeight(height int32) *BlockTreeEntry {
-	tip := c.GetTip()
-	if tip == nil || height > tip.Height() {
+	ptr := C.btck_chain_get_by_height(c.ptr, C.int(height))
+	if ptr == nil {
 		return nil
 	}
-	ptr := C.btck_chain_get_by_height(c.ptr, C.int(height))
-	return &BlockTreeEntry{check(ptr)}
+	return &BlockTreeEntry{ptr}
 }
 
 func (c *Chain) Contains(blockTreeEntry *BlockTreeEntry) bool {

Original file line number	Diff line number	Diff line change
`@@ -29,12 +29,11 @@ func (c Chain) GetGenesis() BlockTreeEntry {`
`29`	`29`
`30`	`30`	`// GetByHeight returns the block tree entry for the given height in the chain, or nil if it does not exist`
`31`	`31`	`func (c Chain) GetByHeight(height int32) BlockTreeEntry {`
`32`		`- tip := c.GetTip()`
`33`		`- if tip == nil \|\| height > tip.Height() {`
	`32`	`+ ptr := C.btck_chain_get_by_height(c.ptr, C.int(height))`
	`33`	`+ if ptr == nil {`
`34`	`34`	`return nil`
`35`	`35`	`}`
`36`		`- ptr := C.btck_chain_get_by_height(c.ptr, C.int(height))`
`37`		`- return &BlockTreeEntry{check(ptr)}`
	`36`	`+ return &BlockTreeEntry{ptr}`
`38`	`37`	`}`
`39`	`38`
`40`	`39`	`func (c Chain) Contains(blockTreeEntry BlockTreeEntry) bool {`