merge: convert empty tree constant to the_hash_algo

bk2204 · gitster · commit e9fe6f262eab · 2018-05-02T13:59:52.000+09:00
To avoid dependency on a particular hash algorithm, convert a use of
EMPTY_TREE_SHA1_HEX to use the_hash_algo-&gt;empty_tree instead.  Since
both branches now use oid_to_hex, condense the if statement into a
ternary.

Signed-off-by: brian m. carlson &lt;sandals@crustytoothpaste.net&gt;
Signed-off-by: Junio C Hamano &lt;gitster@pobox.com&gt;
diff --git a/merge.c b/merge.c
@@ -11,10 +11,7 @@
 
 static const char *merge_argument(struct commit *commit)
 {
-	if (commit)
-		return oid_to_hex(&commit->object.oid);
-	else
-		return EMPTY_TREE_SHA1_HEX;
+	return oid_to_hex(commit ? &commit->object.oid : the_hash_algo->empty_tree);
 }
 
 int index_has_changes(struct strbuf *sb)

Original file line number	Diff line number	Diff line change
`@@ -11,10 +11,7 @@`
`11`	`11`
`12`	`12`	`static const char merge_argument(struct commit commit)`
`13`	`13`	`{`
`14`		`- if (commit)`
`15`		`- return oid_to_hex(&commit->object.oid);`
`16`		`- else`
`17`		`- return EMPTY_TREE_SHA1_HEX;`
	`14`	`+ return oid_to_hex(commit ? &commit->object.oid : the_hash_algo->empty_tree);`
`18`	`15`	`}`
`19`	`16`
`20`	`17`	`int index_has_changes(struct strbuf *sb)`