[PATCH v2 1/2] tarantoolctl: fix cat and play for empty body requests

[Serge Petrenko]

If space.before_replace returns the old tuple, the operation turns into
no-op, but is still written to WAL as IPROTO_NOP for the sake of
replication. Such a request doesn't have a body, and tarantoolctl failed
to parse such requests in `tarantoolctl cat` and `tarantoolctl play`.
Fix this by checking whether a request has a body. Also skip such
requests in `play`, since they have no effect, and, while we're at it,
make sure `play` and `cat` do not read excess rows with lsn>=to in case
these rows are skipped.

Closes #3675
---
 extra/dist/tarantoolctl.in         | 32 ++++++++++++++++++------------
 test/app-tap/tarantoolctl.test.lua | 14 ++++++++++---
 2 files changed, 30 insertions(+), 16 deletions(-)

diff --git a/extra/dist/tarantoolctl.in b/extra/dist/tarantoolctl.in
index 3d7ff3ec5..588ca1729 100755
--- a/extra/dist/tarantoolctl.in
+++ b/extra/dist/tarantoolctl.in
@@ -373,6 +373,12 @@ write_lua_table = function(tuple)
 end
 
 local function cat_lua_cb(record)
+    -- Ignore both versions of IPROTO_NOP: the one without a
+    -- body (new), and the one with empty body (old).
+    if record.HEADER.type == 'NOP' or record.BODY == nil or
+       record.BODY.space_id == nil then
+        return
+    end
     io.stdout:write(('box.space[%d]'):format(record.BODY.space_id))
     local op = record.HEADER.type:lower()
     io.stdout:write((':%s('):format(op))
@@ -816,17 +822,17 @@ local function cat()
     for id, file in ipairs(positional_arguments) do
         log.error("Processing file '%s'", file)
         for lsn, record in xlog.pairs(file) do
-            local sid = record.BODY.space_id
+            local sid = record.BODY and record.BODY.space_id
             local rid = record.HEADER.replica_id
-            if (lsn < from) or
+            if lsn >= to then
+                -- stop, as we've finished reading tuple with lsn == to
+                -- and the next lsn's will be bigger
+                break
+            elseif (lsn < from) or
                (not spaces and sid and sid < 512 and not show_system) or
                (spaces and (sid == nil or not find_in_list(sid, spaces))) or
                (replicas and not find_in_list(rid, replicas)) then
                 -- pass this tuple
-            elseif lsn >= to then
-                -- stop, as we've finished reading tuple with lsn == to
-                -- and the next lsn's will be bigger
-                break
             else
                 is_printed = true
                 format_cb(record)
@@ -857,17 +863,17 @@ local function play()
     for id, file in ipairs(positional_arguments) do
         log.info(("Processing file '%s'"):format(file))
         for lsn, record in xlog.pairs(file) do
-            local sid = record.BODY.space_id
+            local sid = record.BODY and record.BODY.space_id
             local rid = record.HEADER.replica_id
-            if (lsn < from) or
-               (not spaces and sid and sid < 512 and not show_system) or
-               (spaces and (sid == nil or not find_in_list(sid, spaces))) or
-               (replicas and not find_in_list(rid, replicas)) then
-                -- pass this tuple
-            elseif lsn >= to then
+            if lsn >= to then
                 -- stop, as we've finished reading tuple with lsn == to
                 -- and the next lsn's will be bigger
                 break
+            elseif (lsn < from) or sid == nil or
+               (not spaces and sid < 512 and not show_system) or
+               (spaces and not find_in_list(sid, spaces)) or
+               (replicas and not find_in_list(rid, replicas)) then
+                -- pass this tuple
             else
                 local args, so = {}, remote.space[sid]
                 if so == nil then
diff --git a/test/app-tap/tarantoolctl.test.lua b/test/app-tap/tarantoolctl.test.lua
index 340232ace..458e6c030 100755
--- a/test/app-tap/tarantoolctl.test.lua
+++ b/test/app-tap/tarantoolctl.test.lua
@@ -345,6 +345,10 @@ do
         space:update({[1] = 2}, {[1] = {[1] = '\x3d', [2] = 3, [3] = 4}})
         space:upsert({[1] = 3, [2] = 4, [3] = 5, [4] = 6}, {[1] = {[1] = '\x3d', [2] = 3, [3] = 4}})
         space:upsert({[1] = 3, [2] = 4, [3] = 5, [4] = 6}, {[1] = {[1] = '\x3d', [2] = 3, [3] = 4}})
+        f = function(old, new) return old end
+        space:before_replace(f)
+        space:replace{1,5}
+        space:before_replace(nil, f)
         os.exit(0)
     ]]
 
@@ -372,11 +376,11 @@ do
         test:test("fill and test cat output", function(test_i)
             test_i:plan(29)
             check_ok(test_i, dir, 'start', 'filler', 0)
-            check_ctlcat_xlog(test_i, dir, nil, "---\n", 6)
+            check_ctlcat_xlog(test_i, dir, nil, "---\n", 7)
             check_ctlcat_xlog(test_i, dir, "--space=512", "---\n", 6)
             check_ctlcat_xlog(test_i, dir, "--space=666", "---\n", 0)
-            check_ctlcat_xlog(test_i, dir, "--show-system", "---\n", 9)
-            check_ctlcat_xlog(test_i, dir, "--format=json", "\n", 6)
+            check_ctlcat_xlog(test_i, dir, "--show-system", "---\n", 10)
+            check_ctlcat_xlog(test_i, dir, "--format=json", "\n", 7)
             check_ctlcat_xlog(test_i, dir, "--format=lua",  "\n", 6)
             check_ctlcat_xlog(test_i, dir, "--from=3 --to=6 --format=json", "\n", 2)
             check_ctlcat_xlog(test_i, dir, "--from=3 --to=6 --format=json --show-system", "\n", 3)
@@ -411,6 +415,10 @@ do
         space:update({[1] = 2}, {[1] = {[1] = '\x3d', [2] = 3, [3] = 4}})
         space:upsert({[1] = 3, [2] = 4, [3] = 5, [4] = 6}, {[1] = {[1] = '\x3d', [2] = 3, [3] = 4}})
         space:upsert({[1] = 3, [2] = 4, [3] = 5, [4] = 6}, {[1] = {[1] = '\x3d', [2] = 3, [3] = 4}})
+        f = function(old, new) return old end
+        space:before_replace(f)
+        space:replace{1,5}
+        space:before_replace(nil, f)
         os.exit(0)
     ]]
     create_script(dir, 'filler.lua', filler_code)
-- 
2.17.1 (Apple Git-112)