vim-patch:8.1.0369: continuation lines cannot contain comments

Problem:    Continuation lines cannot contain comments.
Solution:   Support using "\ .
https://github.com/vim/vim/commit/67f8ab829911c7901c534ef2bf19cc34b622936f

4 files changed, 54 insertions, 17 deletions

diff --git a/runtime/doc/repeat.txt b/runtime/doc/repeat.txt
index 23ae3458ea..0a552a1309 100644
--- a/runtime/doc/repeat.txt
+++ b/runtime/doc/repeat.txt
@@ -432,6 +432,16 @@ flag when defining the function, it is not relevant when executing it. >
    .
    :endfunction
    :set cpo-=C
+<
+					*line-continuation-comment*
+To add a comment in between the lines start with '\" '.  Notice the space
+after the double quote.  Example: >
+	let array = [
+		"\ first entry comment
+		\ 'first',
+		"\ second entry comment
+		\ 'second',
+		\ ]
 
 Rationale:
 	Most programs work with a trailing backslash to indicate line
@@ -440,6 +450,14 @@ Rationale:
 		:map xx  asdf\
 <	Therefore the unusual leading backslash is used.
 
+	Starting a comment in a continuation line results in all following
+	continuation lines to be part of the comment.  Since it was like this
+	for a long time, when making it possible to add a comment halfway a
+	sequence of continuation lines, it was not possible to use \", since
+	that was a valid continuation line.  Using '"\ ' comes closest, even
+	though it may look a bit weird.  Requiring the space after the
+	backslash is to make it very unlikely this is a normal comment line.
+
 ==============================================================================
 5. Using Vim packages					*packages*
 
diff --git a/runtime/indent/vim.vim b/runtime/indent/vim.vim
index 8ebfa12caf..cd735c3a3c 100644
--- a/runtime/indent/vim.vim
+++ b/runtime/indent/vim.vim
@@ -10,7 +10,7 @@ endif
 let b:did_indent = 1
 
 setlocal indentexpr=GetVimIndent()
-setlocal indentkeys+==end,=else,=cat,=fina,=END,0\\
+setlocal indentkeys+==end,=else,=cat,=fina,=END,0\\,0=\"\\\ 
 
 let b:undo_indent = "setl indentkeys< indentexpr<"
 
@@ -31,15 +31,17 @@ function GetVimIndent()
   endtry
 endfunc
 
+let s:lineContPat = '^\s*\(\\\|"\\ \)'
+
 function GetVimIndentIntern()
   " Find a non-blank line above the current line.
   let lnum = prevnonblank(v:lnum - 1)
 
-  " If the current line doesn't start with '\' and below a line that starts
-  " with '\', use the indent of the line above it.
+  " If the current line doesn't start with '\' or '"\ ' and below a line that
+  " starts with '\' or '"\ ', use the indent of the line above it.
   let cur_text = getline(v:lnum)
-  if cur_text !~ '^\s*\\'
-    while lnum > 0 && getline(lnum) =~ '^\s*\\'
+  if cur_text !~ s:lineContPat
+    while lnum > 0 && getline(lnum) =~ s:lineContPat
       let lnum = lnum - 1
     endwhile
   endif
@@ -51,10 +53,10 @@ function GetVimIndentIntern()
   let prev_text = getline(lnum)
 
   " Add a 'shiftwidth' after :if, :while, :try, :catch, :finally, :function
-  " and :else.  Add it three times for a line that starts with '\' after
-  " a line that doesn't (or g:vim_indent_cont if it exists).
+  " and :else.  Add it three times for a line that starts with '\' or '"\ '
+  " after a line that doesn't (or g:vim_indent_cont if it exists).
   let ind = indent(lnum)
-  if cur_text =~ '^\s*\\' && v:lnum > 1 && prev_text !~ '^\s*\\'
+  if cur_text =~ s:lineContPat && v:lnum > 1 && prev_text !~ s:lineContPat
     if exists("g:vim_indent_cont")
       let ind = ind + g:vim_indent_cont
     else
diff --git a/src/nvim/ex_cmds2.c b/src/nvim/ex_cmds2.c
index 15b735dc9e..53a5018fe0 100644
--- a/src/nvim/ex_cmds2.c
+++ b/src/nvim/ex_cmds2.c
@@ -3403,13 +3403,18 @@ char_u *getsourceline(int c, void *cookie, int indent)
     // Get the next line and concatenate it when it starts with a
     // backslash. We always need to read the next line, keep it in
     // sp->nextline.
+    // Also check for a comment in between continuation lines: "\ .
     sp->nextline = get_one_sourceline(sp);
-    if (sp->nextline != NULL && *(p = skipwhite(sp->nextline)) == '\\') {
+    if (sp->nextline != NULL
+        && (*(p = skipwhite(sp->nextline)) == '\\'
+            || (p[0] == '"' && p[1] == '\\' && p[2] == ' '))) {
       garray_T ga;
 
       ga_init(&ga, (int)sizeof(char_u), 400);
       ga_concat(&ga, line);
-      ga_concat(&ga, p + 1);
+      if (*p == '\\') {
+        ga_concat(&ga, p + 1);
+      }
       for (;; ) {
         xfree(sp->nextline);
         sp->nextline = get_one_sourceline(sp);
@@ -3417,15 +3422,16 @@ char_u *getsourceline(int c, void *cookie, int indent)
           break;
         }
         p = skipwhite(sp->nextline);
-        if (*p != '\\') {
+        if (*p == '\\') {
+          // Adjust the growsize to the current length to speed up
+          // concatenating many lines.
+          if (ga.ga_len > 400) {
+            ga_set_growsize(&ga, (ga.ga_len > 8000) ? 8000 : ga.ga_len);
+          }
+          ga_concat(&ga, p + 1);
+        } else if (p[0] != '"' || p[1] != '\\' || p[2] != ' ') {
           break;
         }
-        // Adjust the growsize to the current length to speed up
-        // concatenating many lines.
-        if (ga.ga_len > 400) {
-          ga_set_growsize(&ga, (ga.ga_len > 8000) ? 8000 : ga.ga_len);
-        }
-        ga_concat(&ga, p + 1);
       }
       ga_append(&ga, NUL);
       xfree(line);
diff --git a/src/nvim/testdir/test_eval_stuff.vim b/src/nvim/testdir/test_eval_stuff.vim
index a99b7e9c0b..1850fb0cf1 100644
--- a/src/nvim/testdir/test_eval_stuff.vim
+++ b/src/nvim/testdir/test_eval_stuff.vim
@@ -38,3 +38,14 @@ func Test_mkdir_p()
   call delete('Xfile')
   call delete('Xmkdir', 'rf')
 endfunc
+
+func Test_line_continuation()
+  let array = [5,
+	"\ ignore this
+	\ 6,
+	"\ more to ignore
+	"\ more moreto ignore
+	\ ]
+	"\ and some more
+  call assert_equal([5, 6], array)
+endfunc