fix clang -Wtautological-compare with unsigned enum

Create a GREP_HEADER_FIELD_MIN so we can check that the field value is
sane and silence the clang warning.

Clang warning happens because the enum is unsigned (this is
implementation-defined, and there is no negative fields) and the check
is then tautological.

Signed-off-by: Antoine Pelisse <apelisse@gmail.com>
Signed-off-by: John Keeping <john@keeping.me.uk>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/grep.c b/grep.c
index 4bd1b8b1dd67e4f5c2223536b435198ce67463ba..bb548cae69d1eece8832c97332a91daac5f8dceb 100644 (file)
--- a/grep.c
+++ b/grep.c
@@ -625,7 +625,8 @@ static struct grep_expr *prep_header_patterns(struct grep_opt *opt)
        for (p = opt->header_list; p; p = p->next) {
                if (p->token != GREP_PATTERN_HEAD)
                        die("bug: a non-header pattern in grep header list.");
-               if (p->field < 0 || GREP_HEADER_FIELD_MAX <= p->field)
+               if (p->field < GREP_HEADER_FIELD_MIN ||
+                   GREP_HEADER_FIELD_MAX <= p->field)
                        die("bug: unknown header field %d", p->field);
                compile_regexp(p, opt);
        }

diff --git a/grep.h b/grep.h
index 8fc854f400802c3329fc3c028942de55b820ac90..e4a1df56a423548af4cba728811eb21b62518e15 100644 (file)
--- a/grep.h
+++ b/grep.h
@@ -28,7 +28,8 @@ enum grep_context {
 };
 
 enum grep_header_field {
-       GREP_HEADER_AUTHOR = 0,
+       GREP_HEADER_FIELD_MIN = 0,
+       GREP_HEADER_AUTHOR = GREP_HEADER_FIELD_MIN,
        GREP_HEADER_COMMITTER,
        GREP_HEADER_REFLOG,