BUG_ON_OPT_NEG(unset);
- options->context = strtol(arg, &s, 10);
- if (*s)
- return error(_("%s expects a numerical value"), "--unified");
+ if (arg) {
+ options->context = strtol(arg, &s, 10);
+ if (*s)
+ return error(_("%s expects a numerical value"), "--unified");
+ }
enable_patch_output(&options->output_format);
return 0;
DIFF_FORMAT_PATCH, DIFF_FORMAT_NO_OUTPUT),
OPT_CALLBACK_F('U', "unified", options, N_("<n>"),
N_("generate diffs with <n> lines context"),
- PARSE_OPT_NONEG, diff_opt_unified),
+ PARSE_OPT_NONEG | PARSE_OPT_OPTARG, diff_opt_unified),
OPT_BOOL('W', "function-context", &options->flags.funccontext,
N_("generate diffs with <n> lines context")),
OPT_BIT_F(0, "raw", &options->output_format,
N_("show the given source prefix instead of \"a/\""),
PARSE_OPT_NONEG),
OPT_STRING_F(0, "dst-prefix", &options->b_prefix, N_("<prefix>"),
- N_("show the given source prefix instead of \"b/\""),
+ N_("show the given destination prefix instead of \"b/\""),
PARSE_OPT_NONEG),
OPT_CALLBACK_F(0, "line-prefix", options, N_("<prefix>"),
N_("prepend an additional prefix to every line of output"),