help.c: refactor drop_prefix() to use a "switch" statement"

Refactor the drop_prefix() function in in help.c to make it easier to
strip prefixes from categories that aren't "CAT_guide". There are no
functional changes here, by doing this we make a subsequent functional
change's diff smaller.

As before we first try to strip "git-" unconditionally, if that works
we'll return the stripped string. Then we'll strip "git" if the
command is in "CAT_guide".

This means that we'd in principle strip "git-foo" down to "foo" if
it's in CAT_guide. That doesn't make much sense, and we don't have
such an entry in command-list.txt, but let's preserve that behavior
for now.

While we're at it remove a stray newline that had been added after the
"return name;" statement.

Signed-off-by: Ævar Arnfjörð Bjarmason <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: avar

help.c

@@ -44,13 +44,19 @@ static struct category_description main_categories[] = {
 static const char *drop_prefix(const char *name, uint32_t category)
 {
 	const char *new_name;
+	const char *prefix = NULL;
 
 	if (skip_prefix(name, "git-", &new_name))
 		return new_name;
-	if (category == CAT_guide && skip_prefix(name, "git", &new_name))
+	switch (category) {
+	case CAT_guide:
+		prefix = "git";
+		break;
+	}
+	if (prefix && skip_prefix(name, prefix, &new_name))
 		return new_name;
-	return name;
 
+	return name;
 }
 
 static void extract_cmds(struct cmdname_help **p_cmds, uint32_t mask)