vim-patch:9.0.0761: cannot use 'indentexpr' for Lisp indenting

Problem:    Cannot use 'indentexpr' for Lisp indenting.
Solution:   Add the 'lispoptions' option.
https://github.com/vim/vim/commit/49846fb1a31de99f49d6a7e70efe685197423c84

vim-patch:9.0.0762: build failure

Problem:    Build failure.
Solution:   Add missing change.
https://github.com/vim/vim/commit/4b082c4bd05f504fda1acaa9d28fca55a2d04857

13 files changed, 107 insertions, 43 deletions

diff --git a/runtime/doc/options.txt b/runtime/doc/options.txt
index a846f49781..3e056ffc28 100644
--- a/runtime/doc/options.txt
+++ b/runtime/doc/options.txt
@@ -3352,7 +3352,7 @@ A jump table for the options with a short description can be found at |Q_op|.
 	in Insert mode as specified with the 'indentkeys' option.
 	When this option is not empty, it overrules the 'cindent' and
 	'smartindent' indenting.  When 'lisp' is set, this option is
-	overridden by the Lisp indentation algorithm.
+	is only used when 'lispoptions' contains "expr:1".
 	When 'paste' is set this option is not used for indenting.
 	The expression is evaluated with |v:lnum| set to the line number for
 	which the indent is to be computed.  The cursor is also in this line
@@ -3719,6 +3719,17 @@ A jump table for the options with a short description can be found at |Q_op|.
 	calling an external program if 'equalprg' is empty.
 	This option is not used when 'paste' is set.
 
+						*'lispoptions'* *'lop'*
+'lispoptions' 'lop'	string	(default "")
+			local to buffer
+	Comma-separated list of items that influence the Lisp indenting when
+	enabled with the |'lisp'| option.  Currently only one item is
+	supported:
+		expr:1	use 'indentexpr' for Lisp indenting when it is set
+		expr:0	do not use 'indentexpr' for Lisp indenting (default)
+	Note that when using 'indentexpr' the `=` operator indents all the
+	lines, otherwise the first line is not indented (Vi-compatible).
+
 						*'lispwords'* *'lw'*
 'lispwords' 'lw'	string	(default is very long)
 			global or local to buffer |global-local|
diff --git a/src/nvim/buffer.c b/src/nvim/buffer.c
index 29b00bad2a..84ff2fa59b 100644
--- a/src/nvim/buffer.c
+++ b/src/nvim/buffer.c
@@ -1959,8 +1959,9 @@ void free_buf_options(buf_T *buf, int free_p_ff)
   clear_string_option(&buf->b_p_ft);
   clear_string_option(&buf->b_p_cink);
   clear_string_option(&buf->b_p_cino);
-  clear_string_option(&buf->b_p_cinw);
+  clear_string_option(&buf->b_p_lop);
   clear_string_option(&buf->b_p_cinsd);
+  clear_string_option(&buf->b_p_cinw);
   clear_string_option(&buf->b_p_cpt);
   clear_string_option(&buf->b_p_cfu);
   clear_string_option(&buf->b_p_ofu);
diff --git a/src/nvim/buffer_defs.h b/src/nvim/buffer_defs.h
index 630e1d14a8..043a31bf16 100644
--- a/src/nvim/buffer_defs.h
+++ b/src/nvim/buffer_defs.h
@@ -699,6 +699,7 @@ struct file_buffer {
   uint32_t b_p_fex_flags;       ///< flags for 'formatexpr'
   char *b_p_kp;                 ///< 'keywordprg'
   int b_p_lisp;                 ///< 'lisp'
+  char *b_p_lop;                ///< 'lispoptions'
   char *b_p_menc;               ///< 'makeencoding'
   char *b_p_mps;                ///< 'matchpairs'
   int b_p_ml;                   ///< 'modeline'
diff --git a/src/nvim/change.c b/src/nvim/change.c
index c6f9e9f5c2..2424a8a2eb 100644
--- a/src/nvim/change.c
+++ b/src/nvim/change.c
@@ -1814,17 +1814,19 @@ int open_line(int dir, int flags, int second_line_indent, bool *did_do_comment)
     vreplace_mode = 0;
   }
 
-  if (!p_paste
-      && leader == NULL
-      && curbuf->b_p_lisp
-      && curbuf->b_p_ai) {
-    // do lisp indenting
-    fixthisline(get_lisp_indent);
-    ai_col = (colnr_T)getwhitecols_curline();
-  } else if (do_cindent) {
-    // do 'cindent' or 'indentexpr' indenting
-    do_c_expr_indent();
-    ai_col = (colnr_T)getwhitecols_curline();
+  if (!p_paste) {
+    if (leader == NULL
+        && !use_indentexpr_for_lisp()
+        && curbuf->b_p_lisp
+        && curbuf->b_p_ai) {
+      // do lisp indenting
+      fixthisline(get_lisp_indent);
+      ai_col = (colnr_T)getwhitecols_curline();
+    } else if (do_cindent || (curbuf->b_p_ai && use_indentexpr_for_lisp())) {
+      // do 'cindent' or 'indentexpr' indenting
+      do_c_expr_indent();
+      ai_col = (colnr_T)getwhitecols_curline();
+    }
   }
 
   if (vreplace_mode != 0) {
diff --git a/src/nvim/edit.c b/src/nvim/edit.c
index 0e14567286..e37f967a2c 100644
--- a/src/nvim/edit.c
+++ b/src/nvim/edit.c
@@ -2993,34 +2993,6 @@ bool cindent_on(void)
   return !p_paste && (curbuf->b_p_cin || *curbuf->b_p_inde != NUL);
 }
 
-// Re-indent the current line, based on the current contents of it and the
-// surrounding lines. Fixing the cursor position seems really easy -- I'm very
-// confused what all the part that handles Control-T is doing that I'm not.
-// "get_the_indent" should be get_c_indent, get_expr_indent or get_lisp_indent.
-void fixthisline(IndentGetter get_the_indent)
-{
-  int amount = get_the_indent();
-
-  if (amount >= 0) {
-    change_indent(INDENT_SET, amount, false, 0, true);
-    if (linewhite(curwin->w_cursor.lnum)) {
-      did_ai = true;  // delete the indent if the line stays empty
-    }
-  }
-}
-
-void fix_indent(void)
-{
-  if (p_paste) {
-    return;
-  }
-  if (curbuf->b_p_lisp && curbuf->b_p_ai) {
-    fixthisline(get_lisp_indent);
-  } else if (cindent_on()) {
-    do_c_expr_indent();
-  }
-}
-
 /// Check that "cinkeys" contains the key "keytyped",
 /// when == '*': Only if key is preceded with '*' (indent before insert)
 /// when == '!': Only if key is preceded with '!' (don't insert)
diff --git a/src/nvim/edit.h b/src/nvim/edit.h
index eda6d8c9db..91c519f015 100644
--- a/src/nvim/edit.h
+++ b/src/nvim/edit.h
@@ -4,8 +4,6 @@
 #include "nvim/autocmd.h"
 #include "nvim/vim.h"
 
-typedef int (*IndentGetter)(void);
-
 // Values for in_cinkeys()
 #define KEY_OPEN_FORW   0x101
 #define KEY_OPEN_BACK   0x102
diff --git a/src/nvim/indent.c b/src/nvim/indent.c
index 3f5a8afbc1..3f08aa7043 100644
--- a/src/nvim/indent.c
+++ b/src/nvim/indent.c
@@ -15,6 +15,7 @@
 #include "nvim/eval.h"
 #include "nvim/extmark.h"
 #include "nvim/indent.h"
+#include "nvim/indent_c.h"
 #include "nvim/mark.h"
 #include "nvim/memline.h"
 #include "nvim/memory.h"
@@ -1144,3 +1145,45 @@ static int lisp_match(char_u *p)
   }
   return false;
 }
+
+/// Re-indent the current line, based on the current contents of it and the
+/// surrounding lines. Fixing the cursor position seems really easy -- I'm very
+/// confused what all the part that handles Control-T is doing that I'm not.
+/// "get_the_indent" should be get_c_indent, get_expr_indent or get_lisp_indent.
+void fixthisline(IndentGetter get_the_indent)
+{
+  int amount = get_the_indent();
+
+  if (amount >= 0) {
+    change_indent(INDENT_SET, amount, false, 0, true);
+    if (linewhite(curwin->w_cursor.lnum)) {
+      did_ai = true;  // delete the indent if the line stays empty
+    }
+  }
+}
+
+/// Return true if 'indentexpr' should be used for Lisp indenting.
+/// Caller may want to check 'autoindent'.
+bool use_indentexpr_for_lisp(void)
+{
+  return curbuf->b_p_lisp
+         && *curbuf->b_p_inde != NUL
+         && strcmp(curbuf->b_p_lop, "expr:1") == 0;
+}
+
+/// Fix indent for 'lisp' and 'cindent'.
+void fix_indent(void)
+{
+  if (p_paste) {
+    return;  // no auto-indenting when 'paste' is set
+  }
+  if (curbuf->b_p_lisp && curbuf->b_p_ai) {
+    if (use_indentexpr_for_lisp()) {
+      do_c_expr_indent();
+    } else {
+      fixthisline(get_lisp_indent);
+    }
+  } else if (cindent_on()) {
+    do_c_expr_indent();
+  }
+}
diff --git a/src/nvim/indent.h b/src/nvim/indent.h
index f96732bf1c..f807bbb42b 100644
--- a/src/nvim/indent.h
+++ b/src/nvim/indent.h
@@ -3,6 +3,8 @@
 
 #include "nvim/vim.h"
 
+typedef int (*IndentGetter)(void);
+
 // flags for set_indent()
 #define SIN_CHANGED     1       // call changed_bytes() when line changed
 #define SIN_INSERT      2       // insert indent before existing text
diff --git a/src/nvim/option.c b/src/nvim/option.c
index 7202156c46..0b819aad43 100644
--- a/src/nvim/option.c
+++ b/src/nvim/option.c
@@ -4008,6 +4008,8 @@ static char_u *get_varp(vimoption_T *p)
     return (char_u *)&(curbuf->b_p_fex);
   case PV_LISP:
     return (char_u *)&(curbuf->b_p_lisp);
+  case PV_LOP:
+    return (char_u *)&(curbuf->b_p_lop);
   case PV_ML:
     return (char_u *)&(curbuf->b_p_ml);
   case PV_MPS:
@@ -4414,6 +4416,8 @@ void buf_copy_options(buf_T *buf, int flags)
       COPY_OPT_SCTX(buf, BV_CINO);
       buf->b_p_cinsd = xstrdup(p_cinsd);
       COPY_OPT_SCTX(buf, BV_CINSD);
+      buf->b_p_lop = xstrdup(p_lop);
+      COPY_OPT_SCTX(buf, BV_LOP);
 
       // Don't copy 'filetype', it must be detected
       buf->b_p_ft = empty_option;
diff --git a/src/nvim/option_defs.h b/src/nvim/option_defs.h
index 196ab865a2..c4333a6f61 100644
--- a/src/nvim/option_defs.h
+++ b/src/nvim/option_defs.h
@@ -580,6 +580,7 @@ EXTERN char_u *p_lm;            // 'langmenu'
 EXTERN long p_lines;            // 'lines'
 EXTERN long p_linespace;        // 'linespace'
 EXTERN int p_lisp;              ///< 'lisp'
+EXTERN char *p_lop;             ///< 'lispoptions'
 EXTERN char_u *p_lispwords;     // 'lispwords'
 EXTERN long p_ls;               // 'laststatus'
 EXTERN long p_stal;             // 'showtabline'
@@ -878,6 +879,7 @@ enum {
   BV_KMAP,
   BV_KP,
   BV_LISP,
+  BV_LOP,
   BV_LW,
   BV_MENC,
   BV_MA,
diff --git a/src/nvim/options.lua b/src/nvim/options.lua
index f4d6c808fa..8a883a09c3 100644
--- a/src/nvim/options.lua
+++ b/src/nvim/options.lua
@@ -1364,6 +1364,14 @@ return {
       defaults={if_true=false}
     },
     {
+      full_name='lispoptions', abbreviation='lop',
+      short_desc=N_("options for lisp indenting"),
+      type='string', list='onecomma', scope={'buffer'},
+      deny_duplicates=true,
+      varname='p_lop', pv_name='p_lop',
+      defaults={if_true=''}
+    },
+    {
       full_name='lispwords', abbreviation='lw',
       short_desc=N_("words that change how lisp indenting works"),
       type='string', list='onecomma', scope={'global', 'buffer'},
diff --git a/src/nvim/optionstr.c b/src/nvim/optionstr.c
index be3e137b69..43628d2842 100644
--- a/src/nvim/optionstr.c
+++ b/src/nvim/optionstr.c
@@ -228,6 +228,7 @@ void check_buf_options(buf_T *buf)
   check_string_option(&buf->b_p_cink);
   check_string_option(&buf->b_p_cino);
   parse_cino(buf);
+  check_string_option(&buf->b_p_lop);
   check_string_option(&buf->b_p_ft);
   check_string_option(&buf->b_p_cinw);
   check_string_option(&buf->b_p_cinsd);
@@ -1378,6 +1379,10 @@ char *did_set_string_option(int opt_idx, char **varp, char *oldval, char *errbuf
   } else if (gvarp == &p_cino) {  // 'cinoptions'
     // TODO(vim): recognize errors
     parse_cino(curbuf);
+  } else if (gvarp == &p_lop) {  // 'lispoptions'
+    if (**varp != NUL && strcmp(*varp, "expr:0") != 0 && strcmp(*varp, "expr:1") != 0) {
+      errmsg = e_invarg;
+    }
   } else if (varp == &p_icm) {  // 'inccommand'
     if (check_opt_strings(p_icm, p_icm_values, false) != OK) {
       errmsg = e_invarg;
diff --git a/src/nvim/testdir/test_lispindent.vim b/src/nvim/testdir/test_lispindent.vim
index 8987f67a80..2d6060bba3 100644
--- a/src/nvim/testdir/test_lispindent.vim
+++ b/src/nvim/testdir/test_lispindent.vim
@@ -97,8 +97,23 @@ func Test_lispindent_with_indentexpr()
   exe "normal a(x\<CR>1\<CR>2)\<Esc>"
   let expected = ['(x', '  1', '  2)']
   call assert_equal(expected, getline(1, 3))
+  " with Lisp indenting the first line is not indented
   normal 1G=G
   call assert_equal(expected, getline(1, 3))
+
+  %del
+  setl lispoptions=expr:1 indentexpr=5
+  exe "normal a(x\<CR>1\<CR>2)\<Esc>"
+  let expected_expr = ['(x', '     1', '     2)']
+  call assert_equal(expected_expr, getline(1, 3))
+  normal 2G2<<=G
+  call assert_equal(expected_expr, getline(1, 3))
+
+  setl lispoptions=expr:0
+  " with Lisp indenting the first line is not indented
+  normal 1G3<<=G
+  call assert_equal(expected, getline(1, 3))
+
   bwipe!
 endfunc