vim-patch:8.0.0151,3,4 #7389

vim-patch:8.0.0151
Problem:    To pass buffer content to system() and systemlist() one has to
            first create a string or list.
Solution:   Allow passing a buffer number. (LemonBoy,
            closes vim/vim#1240)
https://github.com/vim/vim/commit/12c4492dd35e0cd83c8816be2ec849b836109882

vim-patch:8.0.0153
Problem:    system() test fails on MS-Windows.
Solution:   Deal when extra space and CR.
https://github.com/vim/vim/commit/9d9c35651712b88c81f1ae11091de1fd0bbbd35c

vim-patch:8.0.0154
Problem:    system() test fails on OS/X.
Solution:   Deal with leading spaces.
https://github.com/vim/vim/commit/31f19ce0a052f7c76d44a9a190e468c79cf5d56d

6 files changed, 101 insertions, 13 deletions

diff --git a/runtime/doc/eval.txt b/runtime/doc/eval.txt
index ae62498d35..7820b85bf4 100644
--- a/runtime/doc/eval.txt
+++ b/runtime/doc/eval.txt
@@ -7645,6 +7645,9 @@ system({cmd} [, {input}])				*system()* *E677*
 		|writefile()| does with {binary} set to "b" (i.e. with
 		a newline between each list item, and newlines inside list
 		items converted to NULs).
+		When {input} is given and is a valid buffer id, the content of
+		the buffer is written to the file line by line, each line
+		terminated by a NL (and NUL where the text has NL).
 								*E5677*
 		Note: system() cannot write to or read from backgrounded ("&")
 		shell commands, e.g.: >
diff --git a/src/nvim/eval.c b/src/nvim/eval.c
index 0d84957ac5..9de6a7c464 100644
--- a/src/nvim/eval.c
+++ b/src/nvim/eval.c
@@ -17482,24 +17482,24 @@ write_list_error:
 
 /// Saves a typval_T as a string.
 ///
-/// For lists, replaces NLs with NUL and separates items with NLs.
+/// For lists or buffers, replaces NLs with NUL and separates items with NLs.
 ///
-/// @param[in]  tv   A value to store as a string.
-/// @param[out] len  The length of the resulting string or -1 on error.
+/// @param[in]  tv   Value to store as a string.
+/// @param[out] len  Length of the resulting string or -1 on error.
 /// @param[in]  endnl If true, the output will end in a newline (if a list).
 /// @returns an allocated string if `tv` represents a VimL string, list, or
 ///          number; NULL otherwise.
 static char *save_tv_as_string(typval_T *tv, ptrdiff_t *const len, bool endnl)
   FUNC_ATTR_MALLOC FUNC_ATTR_NONNULL_ALL
 {
+  *len = 0;
   if (tv->v_type == VAR_UNKNOWN) {
-    *len = 0;
     return NULL;
   }
 
-  // For types other than list, let tv_get_string_buf_chk() get the value or
+  // For other types, let tv_get_string_buf_chk() get the value or
   // print an error.
-  if (tv->v_type != VAR_LIST) {
+  if (tv->v_type != VAR_LIST && tv->v_type != VAR_NUMBER) {
     const char *ret = tv_get_string_chk(tv);
     if (ret && (*len = strlen(ret))) {
       return xmemdupz(ret, (size_t)(*len));
@@ -17509,8 +17509,40 @@ static char *save_tv_as_string(typval_T *tv, ptrdiff_t *const len, bool endnl)
     }
   }
 
+  if (tv->v_type == VAR_NUMBER) {  // Treat number as a buffer-id.
+    buf_T *buf = buflist_findnr(tv->vval.v_number);
+    if (buf) {
+      for (linenr_T lnum = 1; lnum <= buf->b_ml.ml_line_count; lnum++) {
+        for (char_u *p = ml_get_buf(buf, lnum, false); *p != NUL; p++) {
+          *len += 1;
+        }
+        *len += 1;
+      }
+    } else {
+      EMSGN(_(e_nobufnr), tv->vval.v_number);
+      *len = -1;
+      return NULL;
+    }
+
+    if (*len == 0) {
+      return NULL;
+    }
+
+    char *ret = xmalloc(*len + 1);
+    char *end = ret;
+    for (linenr_T lnum = 1; lnum <= buf->b_ml.ml_line_count; lnum++) {
+      for (char_u *p = ml_get_buf(buf, lnum, false); *p != NUL; p++) {
+        *end++ = (*p == '\n') ? NUL : *p;
+      }
+      *end++ = '\n';
+    }
+    *end = NUL;
+    *len = end - ret;
+    return ret;
+  }
+
+  assert(tv->v_type == VAR_LIST);
   // Pre-calculate the resulting length.
-  *len = 0;
   list_T *list = tv->vval.v_list;
   TV_LIST_ITER_CONST(list, li, {
     *len += strlen(tv_get_string(TV_LIST_ITEM_TV(li))) + 1;
diff --git a/src/nvim/testdir/Makefile b/src/nvim/testdir/Makefile
index 0c25945274..c1e6eedf94 100644
--- a/src/nvim/testdir/Makefile
+++ b/src/nvim/testdir/Makefile
@@ -88,6 +88,7 @@ NEW_TESTS ?= \
 	    test_startup_utf8.res \
 	    test_substitute.res \
 	    test_syntax.res \
+	    test_system.res \
 	    test_tabpage.res \
 	    test_textobjects.res \
 	    test_timers.res \
diff --git a/src/nvim/testdir/test_system.vim b/src/nvim/testdir/test_system.vim
new file mode 100644
index 0000000000..0446bd9105
--- /dev/null
+++ b/src/nvim/testdir/test_system.vim
@@ -0,0 +1,48 @@
+" Tests for system() and systemlist()
+
+function! Test_System()
+  if !executable('echo') || !executable('cat') || !executable('wc')
+    return
+  endif
+  let out = system('echo 123')
+  " On Windows we may get a trailing space.
+  if out != "123 \n"
+    call assert_equal("123\n", out)
+  endif
+
+  let out = systemlist('echo 123')
+  " On Windows we may get a trailing space and CR.
+  if out != ["123 \r"]
+    call assert_equal(['123'], out)
+  endif
+
+  call assert_equal('123',   system('cat', '123'))
+  call assert_equal(['123'], systemlist('cat', '123'))
+  call assert_equal(["as\<NL>df"], systemlist('cat', ["as\<NL>df"]))
+
+  new Xdummy
+  call setline(1, ['asdf', "pw\<NL>er", 'xxxx'])
+  let out = system('wc -l', bufnr('%'))
+  " On OS/X we get leading spaces
+  let out = substitute(out, '^ *', '', '')
+  call assert_equal("3\n", out)
+
+  let out = systemlist('wc -l', bufnr('%'))
+  " On Windows we may get a trailing CR.
+  if out != ["3\r"]
+    " On OS/X we get leading spaces
+    if type(out) == v:t_list
+      let out[0] = substitute(out[0], '^ *', '', '')
+    endif
+    call assert_equal(['3'],  out)
+  endif
+
+  let out = systemlist('cat', bufnr('%'))
+  " On Windows we may get a trailing CR.
+  if out != ["asdf\r", "pw\<NL>er\r", "xxxx\r"]
+    call assert_equal(['asdf', "pw\<NL>er", 'xxxx'],  out)
+  endif
+  bwipe!
+
+  call assert_fails('call system("wc -l", 99999)', 'E86:')
+endfunction
diff --git a/src/nvim/version.c b/src/nvim/version.c
index 996c06c902..2181f13c41 100644
--- a/src/nvim/version.c
+++ b/src/nvim/version.c
@@ -1281,10 +1281,10 @@ static const int included_patches[] = {
   157,
   156,
   155,
-  // 154,
-  // 153,
+  154,
+  153,
   152,
-  // 151,
+  151,
   150,
   149,
   148,
diff --git a/test/functional/eval/system_spec.lua b/test/functional/eval/system_spec.lua
index e2b12b6bc9..4d1630042b 100644
--- a/test/functional/eval/system_spec.lua
+++ b/test/functional/eval/system_spec.lua
@@ -5,6 +5,7 @@ local eq, call, clear, eval, feed_command, feed, nvim =
   helpers.eq, helpers.call, helpers.clear, helpers.eval, helpers.feed_command,
   helpers.feed, helpers.nvim
 local command = helpers.command
+local exc_exec = helpers.exc_exec
 local iswin = helpers.iswin
 
 local Screen = require('test.functional.ui.screen')
@@ -274,9 +275,12 @@ describe('system()', function()
     end)
   end)
 
-  describe('input passed as Number', function()
-    it('stringifies the input', function()
-      eq('1', eval('system("cat", 1)'))
+  describe('Number input', function()
+    it('is treated as a buffer id', function()
+      command("put ='text in buffer 1'")
+      eq('\ntext in buffer 1\n', eval('system("cat", 1)'))
+      eq('Vim(echo):E86: Buffer 42 does not exist',
+         exc_exec('echo system("cat", 42)'))
     end)
   end)