grep -An -Bm: fix invocation of external grep command

When building command line to invoke external grep, the
arguments to -A/-B/-C options were placd in randarg[] buffer,
but the code forgot that snprintf() does not count terminating
NUL in its return value.  This caused "git grep -A1 -B2" to
invoke external grep with "-B21 -A1".

Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin-grep.c b/builtin-grep.c
index 185876b0a6dc191bb5adc22cd5c2f012cd70e479..bbf747fc7b66f6b4f19d9dc62a9ba10965199917 100644 (file)
--- a/builtin-grep.c
+++ b/builtin-grep.c
@@ -294,7 +294,7 @@ static int external_grep(struct grep_opt *opt, const char **paths, int cached)
                        if (opt->pre_context) {
                                push_arg("-B");
                                len += snprintf(argptr, sizeof(randarg)-len,
                        if (opt->pre_context) {
                                push_arg("-B");
                                len += snprintf(argptr, sizeof(randarg)-len,

-                                               "%u", opt->pre_context);
+                                               "%u", opt->pre_context) + 1;

                                if (sizeof(randarg) <= len)
                                        die("maximum length of args exceeded");
                                push_arg(argptr);
                                if (sizeof(randarg) <= len)
                                        die("maximum length of args exceeded");
                                push_arg(argptr);


@@ -303,7 +303,7 @@ static int external_grep(struct grep_opt *opt, const char **paths, int cached)
                        if (opt->post_context) {
                                push_arg("-A");
                                len += snprintf(argptr, sizeof(randarg)-len,
                        if (opt->post_context) {
                                push_arg("-A");
                                len += snprintf(argptr, sizeof(randarg)-len,

-                                               "%u", opt->post_context);
+                                               "%u", opt->post_context) + 1;

                                if (sizeof(randarg) <= len)
                                        die("maximum length of args exceeded");
                                push_arg(argptr);
                                if (sizeof(randarg) <= len)
                                        die("maximum length of args exceeded");
                                push_arg(argptr);


@@ -313,7 +313,7 @@ static int external_grep(struct grep_opt *opt, const char **paths, int cached)
                else {
                        push_arg("-C");
                        len += snprintf(argptr, sizeof(randarg)-len,
                else {
                        push_arg("-C");
                        len += snprintf(argptr, sizeof(randarg)-len,

-                                       "%u", opt->post_context);
+                                       "%u", opt->post_context) + 1;

                        if (sizeof(randarg) <= len)
                                die("maximum length of args exceeded");
                        push_arg(argptr);
                        if (sizeof(randarg) <= len)
                                die("maximum length of args exceeded");
                        push_arg(argptr);