[Tarantool-patches] [PATCHv4 2/2] lua: fix tarantool -e always enters interactive mode

[Artem Starshov via Tarantool-patches <tarantool-patches@dev.tarantool.org>]

The reason why tarantool -e always enters interactive mode is that
statement after option -e isn't considered as a script.

In man PUC-Rio lua there are different names for statement -e (stat)
and script, but they have the same behavior regarding interactive
mode. (Also cases, when interpreter loads stdin, have the same behaviour).

NOTE: test for this code fix uses errinjs, and the last one  should work only
in debug mode, so added `release_disabled` in suite.ini. But there is a bug in
test-run: `release_disable` disables tests at each build type. Partially this
problem is descripted in tarantool/test-run#199.

Fixes #5040
---
 .../unreleased/fix-tarantool-e-option.md      |   6 +
 src/lib/core/errinj.h                         |   1 +
 src/lua/init.c                                |  27 +++-
 ...5040-inter-mode-isatty-via-errinj.test.lua | 126 ++++++++++++++++++
 test/app-tap/suite.ini                        |   1 +
 test/box/errinj.result                        |   1 +
 6 files changed, 158 insertions(+), 4 deletions(-)
 create mode 100644 changelogs/unreleased/fix-tarantool-e-option.md
 create mode 100755 test/app-tap/gh-5040-inter-mode-isatty-via-errinj.test.lua

diff --git a/changelogs/unreleased/fix-tarantool-e-option.md b/changelogs/unreleased/fix-tarantool-e-option.md
new file mode 100644
index 000000000..ebabe8c78
--- /dev/null
+++ b/changelogs/unreleased/fix-tarantool-e-option.md
@@ -0,0 +1,6 @@
+## bugfix/lua
+
+* Fixed -e option, when tarantool always entered interactive mode
+  when stdin is a tty. Now, `tarantool -e 'print"Hello"'` doesn't
+  enter interactive mode as it was before, just prints 'Hello' and
+  exits (gh-5040).
diff --git a/src/lib/core/errinj.h b/src/lib/core/errinj.h
index 10edbe2b9..f131a5cf6 100644
--- a/src/lib/core/errinj.h
+++ b/src/lib/core/errinj.h
@@ -149,6 +149,7 @@ struct errinj {
 	_(ERRINJ_AUTO_UPGRADE, ERRINJ_BOOL, {.bparam = false})\
 	_(ERRINJ_COIO_WRITE_CHUNK, ERRINJ_BOOL, {.bparam = false}) \
 	_(ERRINJ_APPLIER_SLOW_ACK, ERRINJ_BOOL, {.bparam = false}) \
+	_(ERRINJ_STDIN_ISATTY, ERRINJ_INT, {.iparam = -1}) \
 
 ENUM0(errinj_id, ERRINJ_LIST);
 extern struct errinj errinjs[];
diff --git a/src/lua/init.c b/src/lua/init.c
index 25e8884a6..4729ad7a2 100644
--- a/src/lua/init.c
+++ b/src/lua/init.c
@@ -62,6 +62,7 @@
 #include "lua/swim.h"
 #include "lua/decimal.h"
 #include "digest.h"
+#include "errinj.h"
 #include <small/ibuf.h>
 
 #include <ctype.h>
@@ -583,6 +584,7 @@ run_script_f(va_list ap)
 	 */
 	struct diag *diag = va_arg(ap, struct diag *);
 	bool aux_loop_is_run = false;
+	bool is_option_e_ran = false;
 
 	/*
 	 * Load libraries and execute chunks passed by -l and -e
@@ -613,6 +615,7 @@ run_script_f(va_list ap)
 			if (luaT_call(L, 0, 0) != 0)
 				goto error;
 			lua_settop(L, 0);
+			is_option_e_ran = true;
 			break;
 		default:
 			unreachable(); /* checked by getopt() in main() */
@@ -627,25 +630,41 @@ run_script_f(va_list ap)
 	fiber_sleep(0.0);
 	aux_loop_is_run = true;
 
+	/*
+	 * Override return value of isatty(STDIN_FILENO) if
+	 * ERRINJ_STDIN_ISATTY enabled (iparam not set to default).
+	 * Use iparam in such case, standard return value otherwise.
+	 * Integer param of errinj is used in order to set different
+	 * return values.
+	*/
+	int is_a_tty;
+	struct errinj *inj = errinj(ERRINJ_STDIN_ISATTY, ERRINJ_INT);
+	if (inj != NULL && inj->iparam >= 0) {
+		is_a_tty = inj->iparam;
+	} else {
+		is_a_tty = isatty(STDIN_FILENO);
+	}
+
 	if (path && strcmp(path, "-") != 0 && access(path, F_OK) == 0) {
 		/* Execute script. */
 		if (luaL_loadfile(L, path) != 0)
 			goto luajit_error;
 		if (lua_main(L, argc, argv) != 0)
 			goto error;
-	} else if (!isatty(STDIN_FILENO) || (path && strcmp(path, "-") == 0)) {
+	} else if (!is_a_tty || (path && strcmp(path, "-") == 0)) {
 		/* Execute stdin */
 		if (luaL_loadfile(L, NULL) != 0)
 			goto luajit_error;
 		if (lua_main(L, argc, argv) != 0)
 			goto error;
-	} else {
+	} else if (!is_option_e_ran) {
 		interactive = true;
 	}
 
 	/*
-	 * Start interactive mode when it was explicitly requested
-	 * by "-i" option or stdin is TTY or there are no script.
+	 * Start interactive mode in any of the cases:
+	 * - it was explicitly requested by "-i" option;
+	 * - stdin is TTY and there are no script (-e is considered as a script).
 	 */
 	if (interactive) {
 		say_crit("%s %s\ntype 'help' for interactive help",
diff --git a/test/app-tap/gh-5040-inter-mode-isatty-via-errinj.test.lua b/test/app-tap/gh-5040-inter-mode-isatty-via-errinj.test.lua
new file mode 100755
index 000000000..25e2bbc5e
--- /dev/null
+++ b/test/app-tap/gh-5040-inter-mode-isatty-via-errinj.test.lua
@@ -0,0 +1,126 @@
+#!/usr/bin/env tarantool
+
+local process_timeout = require('process_timeout')
+local ffi = require('ffi')
+local tap = require('tap')
+local fio = require('fio')
+
+--
+-- Tests to check if the tarantool binary enters
+-- interactive mode or not using error injections
+-- to change return value of isatty(stdin).
+--
+
+local TARANTOOL_PATH = arg[-1]
+local output_file = fio.abspath('out.txt')
+local cmd_end = (' >%s & echo $!'):format(output_file)
+
+-- Like a default timeout for `cond_wait` in test-run
+local process_waiting_timeout = 60.0
+local file_read_timeout = 60.0
+local file_read_interval = 0.2
+local file_open_timeout = 60.0
+
+-- Each testcase consists of:
+--  * cmd_args - command line arguments for tarantool binary
+--  * stdin - stdin for tarantool
+--  * interactive - true if interactive mode expected
+--  * empty_output - true if command should have empty output
+local testcases = {
+    {
+        cmd_args = '',
+        stdin = 'tty',
+        interactive = true
+    },
+    {
+        cmd_args = '',
+        stdin = '/dev/null',
+        interactive = false,
+        empty_output = true
+    },
+
+    {
+        cmd_args = ' -e "print(_VERSION)"',
+        stdin = 'tty',
+        interactive = false
+    },
+    {
+        cmd_args = ' -e "print(_VERSION)"',
+        stdin = '/dev/null',
+        interactive = false
+    },
+
+    {
+        cmd_args = ' -i -e "print(_VERSION)"',
+        stdin = 'tty',
+        interactive = true
+    },
+    {
+        cmd_args = ' -i -e "print(_VERSION)"',
+        stdin = '/dev/null',
+        interactive = true
+    }
+}
+
+local test = tap.test('gh-5040')
+
+test:plan(#testcases)
+for _, cmd in pairs(testcases) do
+    local full_cmd = ''
+    if cmd.stdin == 'tty' then
+        cmd.stdin = ''
+        full_cmd = 'ERRINJ_STDIN_ISATTY=1 '
+    else
+        cmd.stdin = '< ' .. cmd.stdin
+    end
+
+    local full_cmd = full_cmd .. ('%s %s %s %s'):format(
+            TARANTOOL_PATH,
+            cmd.cmd_args,
+            cmd.stdin,
+            cmd_end
+    )
+    test:test(full_cmd, function(test)
+        test:plan(cmd.interactive and 1 or 2)
+
+        local pid = tonumber(io.popen(full_cmd):read("*line"))
+        assert(pid, "pipe error for: " .. cmd.cmd_args)
+
+        local fh = process_timeout.open_with_timeout(output_file,
+                file_open_timeout)
+        assert(fh, 'error while opening ' .. output_file)
+
+        if cmd.interactive then
+            local data = process_timeout.read_with_timeout(fh,
+                    file_read_timeout,
+                    file_read_interval)
+            test:like(data, 'tarantool>', 'interactive mode detected')
+        else
+            local process_completed = process_timeout.wait_process_completion(
+                    pid,
+                    process_waiting_timeout)
+            test:ok(process_completed, 'process completed')
+
+            -- If empty output expected, then don't wait full file_read_timeout
+            -- for non-empty output_file, only a little time to be sure that
+            -- file is empty.
+            local read_timeout = cmd.empty_output and file_read_interval
+                    or file_read_timeout
+            local data = process_timeout.read_with_timeout(fh, read_timeout,
+                    file_read_interval)
+            if cmd.empty_output then
+                test:ok(#data == 0, 'output is empty')
+            else
+                test:unlike(data, 'tarantool>',
+                        'iteractive mode wasn\'t detected')
+            end
+        end
+        if process_timeout.process_is_alive(pid) then
+            ffi.C.kill(pid, 9)
+        end
+        fh:close()
+        os.remove(output_file)
+    end)
+end
+
+os.exit(test:check() and 0 or 1)
diff --git a/test/app-tap/suite.ini b/test/app-tap/suite.ini
index ccf828503..f791ddc5e 100644
--- a/test/app-tap/suite.ini
+++ b/test/app-tap/suite.ini
@@ -5,6 +5,7 @@ lua_libs = lua/require_mod.lua lua/serializer_test.lua lua/process_timeout.lua
 is_parallel = True
 pretest_clean = True
 use_unix_sockets_iproto = True
+release_disabled = gh-5040-inter-mode-isatty-via-errinj.test.lua
 fragile = {
     "retries": 10,
     "tests": {
diff --git a/test/box/errinj.result b/test/box/errinj.result
index b8c2476c3..a962dbe2d 100644
--- a/test/box/errinj.result
+++ b/test/box/errinj.result
@@ -74,6 +74,7 @@ evals
   - ERRINJ_SNAP_COMMIT_DELAY: false
   - ERRINJ_SNAP_WRITE_DELAY: false
   - ERRINJ_SQL_NAME_NORMALIZATION: false
+  - ERRINJ_STDIN_ISATTY: -1
   - ERRINJ_SWIM_FD_ONLY: false
   - ERRINJ_TESTING: false
   - ERRINJ_TUPLE_ALLOC: false
-- 
2.28.0