[PATCH 4/6] fsck: tighten error-checks of "git fsck "

[Jeff King]

Instead of checking reachability from the refs, you can ask
fsck to check from a particular set of heads. However, the
error checking here is quite lax. In particular:

  1. It claims lookup_object() will report an error, which
     is not true. It only does a hash lookup, and the user
     has no clue that their argument was skipped.

  2. When either the name or sha1 cannot be resolved, we
     continue to exit with a successful error code, even
     though we didn't check what the user asked us to.

This patch fixes both of these cases.

Signed-off-by: Jeff King <p...@peff.net>
---
 builtin/fsck.c  | 7 +++++--
 t/t1450-fsck.sh | 5 +++++
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/builtin/fsck.c b/builtin/fsck.c
index f527d8a02..c7d0590e5 100644
--- a/builtin/fsck.c
+++ b/builtin/fsck.c
@@ -755,9 +755,11 @@ int cmd_fsck(int argc, const char **argv, const char 
*prefix)
                if (!get_sha1(arg, sha1)) {
                        struct object *obj = lookup_object(sha1);
 
-                       /* Error is printed by lookup_object(). */
-                       if (!obj)
+                       if (!obj) {
+                               error("%s: object missing", sha1_to_hex(sha1));
+                               errors_found |= ERROR_OBJECT;
                                continue;
+                       }
 
                        obj->used = 1;
                        if (name_objects)
@@ -768,6 +770,7 @@ int cmd_fsck(int argc, const char **argv, const char 
*prefix)
                        continue;
                }
                error("invalid parameter: expected sha1, got '%s'", arg);
+               errors_found |= ERROR_OBJECT;
        }
 
        /*
diff --git a/t/t1450-fsck.sh b/t/t1450-fsck.sh
index c1b2dda33..2f3b05276 100755
--- a/t/t1450-fsck.sh
+++ b/t/t1450-fsck.sh
@@ -605,4 +605,9 @@ test_expect_success 'fsck notices dangling objects' '
        )
 '
 
+test_expect_success 'fsck $name notices bogus $name' '
+       test_must_fail git fsck bogus &&
+       test_must_fail git fsck $_z40
+'
+
 test_done
-- 
2.11.0.642.gd6f8cda6c