[PATCH 6/9] streaming_write_entry: propagate streaming errors

[Jeff King <peff@peff.net>]

When we are streaming an index blob to disk, we store the
error from stream_blob_to_fd in the "result" variable, and
then immediately overwrite that with the return value of
"close". That means we catch errors on close (e.g., problems
committing the file to disk), but miss anything which
happened before then.

Signed-off-by: Jeff King <peff@peff.net>
---
 entry.c                      |  6 ++++--
 t/t1060-object-corruption.sh | 25 +++++++++++++++++++++++++
 2 files changed, 29 insertions(+), 2 deletions(-)

diff --git a/entry.c b/entry.c
index 17a6bcc..002b2f2 100644
--- a/entry.c
+++ b/entry.c
@@ -126,8 +126,10 @@ static int streaming_write_entry(struct cache_entry *ce, char *path,
 	fd = open_output_fd(path, ce, to_tempfile);
 	if (0 <= fd) {
 		result = stream_blob_to_fd(fd, ce->sha1, filter, 1);
-		*fstat_done = fstat_output(fd, state, statbuf);
-		result = close(fd);
+		if (!result) {
+			*fstat_done = fstat_output(fd, state, statbuf);
+			result = close(fd);
+		}
 	}
 	if (result && 0 <= fd)
 		unlink(path);
diff --git a/t/t1060-object-corruption.sh b/t/t1060-object-corruption.sh
index d36994a..0792132 100755
--- a/t/t1060-object-corruption.sh
+++ b/t/t1060-object-corruption.sh
@@ -24,6 +24,15 @@ test_expect_success 'setup corrupt repo' '
 	)
 '
 
+test_expect_success 'setup repo with missing object' '
+	git init missing &&
+	(
+		cd missing &&
+		test_commit content &&
+		rm -f "$(obj_to_file HEAD:content.t)"
+	)
+'
+
 test_expect_success 'streaming a corrupt blob fails' '
 	(
 		cd bit-error &&
@@ -31,4 +40,20 @@ test_expect_success 'streaming a corrupt blob fails' '
 	)
 '
 
+test_expect_success 'read-tree -u detects bit-errors in blobs' '
+	(
+		cd bit-error &&
+		rm content.t &&
+		test_must_fail git read-tree --reset -u FETCH_HEAD
+	)
+'
+
+test_expect_success 'read-tree -u detects missing objects' '
+	(
+		cd missing &&
+		rm content.t &&
+		test_must_fail git read-tree --reset -u FETCH_HEAD
+	)
+'
+
 test_done
-- 
1.8.2.13.g0f18d3c