git-p4: Unset P4DIFF environment variable when using 'p4 -du diff'

diff --git a/builtin-show-branch.c b/builtin-show-branch.c
index 6dc835d30a6a726c3dd40d23564b0dc32d20b7db..019abd3527e7c573c69900a58313749e2ef2280a 100644 (file)
--- a/builtin-show-branch.c
+++ b/builtin-show-branch.c
@@ -536,6 +536,8 @@ static void append_one_rev(const char *av)
 static int git_show_branch_config(const char *var, const char *value)
 {
        if (!strcmp(var, "showbranch.default")) {
+               if (!value)
+                       return config_error_nonbool(var);
                if (default_alloc <= default_num + 1) {
                        default_alloc = default_alloc * 3 / 2 + 20;
                        default_arg = xrealloc(default_arg, sizeof *default_arg * default_alloc);