t1006: add tests for %(objectsize:disk)

Back when we added this placeholder in a4ac106 (cat-file: add
%(objectsize:disk) format atom, 2013-07-10), there were no tests,
claiming "[...]the exact numbers returned are volatile and subject to
zlib and packing decisions".

But we can use a little shell hackery to get the expected numbers
ourselves. To a certain degree this is just re-implementing what Git is
doing under the hood, but it is still worth doing. It makes sure we
exercise the %(objectsize:disk) code at all, and having the two
implementations agree gives us more confidence.

Note that our shell code assumes that no object appears twice (either in
two packs, or as both loose and packed), as then the results really are
undefined. That's OK for our purposes, and the test will notice if that
assumption is violated (the shell version would produce duplicate lines
that Git's output does not have).

Helped-by: René Scharfe <[email protected]>
Signed-off-by: Jeff King <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: peff

t/t1006-cat-file.sh

@@ -1100,6 +1100,40 @@ test_expect_success 'cat-file --batch="batman" with --batch-all-objects will wor
 	cmp expect actual
 '
 
+test_expect_success 'cat-file %(objectsize:disk) with --batch-all-objects' '
+	# our state has both loose and packed objects,
+	# so find both for our expected output
+	{
+		find .git/objects/?? -type f |
+		awk -F/ "{ print \$0, \$3\$4 }" |
+		while read path oid
+		do
+			size=$(test_file_size "$path") &&
+			echo "$oid $size" ||
+			return 1
+		done &&
+		rawsz=$(test_oid rawsz) &&
+		find .git/objects/pack -name "*.idx" |
+		while read idx
+		do
+			git show-index <"$idx" >idx.raw &&
+			sort -n <idx.raw >idx.sorted &&
+			packsz=$(test_file_size "${idx%.idx}.pack") &&
+			end=$((packsz - rawsz)) &&
+			awk -v end="$end" "
+			  NR > 1 { print oid, \$1 - start }
+			  { start = \$1; oid = \$2 }
+			  END { print oid, end - start }
+			" idx.sorted ||
+			return 1
+		done
+	} >expect.raw &&
+	sort <expect.raw >expect &&
+	git cat-file --batch-all-objects \
+		--batch-check="%(objectname) %(objectsize:disk)" >actual &&
+	test_cmp expect actual
+'
+
 test_expect_success 'set up replacement object' '
 	orig=$(git rev-parse HEAD) &&
 	git cat-file commit $orig >orig &&