vim-patch:8.2.2772: problems when restoring 'runtimepath' from a session file

Problem:    Problems when restoring 'runtimepath' from a session file.
Solution:   Add the "skiprtp" item in 'sessionoptions'.
635bd60804

Allow "terminal" value for sessionoptions even if it's no-opt
because patch v8.0.1592 is not ported yet.

Omit vim9 test, Test_mksession_skiprtp().

runtime/doc/options.txt

@@ -5052,6 +5052,7 @@ A jump table for the options with a short description can be found at |Q_op|.
 			global values for local options)
 	   options	all options and mappings (also global values for local
 			options)
+	   skiprtp	exclude 'runtimepath' from the options
 	   resize	size of the Vim window: 'lines' and 'columns'
 	   sesdir	the directory in which the session file is located
 			will become the current directory (useful with

src/nvim/ex_session.c

@@ -937,8 +937,13 @@ void ex_mkrc(exarg_T *eap)
 
     if (!view_session || (eap->cmdidx == CMD_mksession
                           && (*flagp & SSOP_OPTIONS))) {
+      int flags = OPT_GLOBAL;
+
+      if (eap->cmdidx == CMD_mksession && (*flagp & SSOP_SKIP_RTP)) {
+        flags |= OPT_SKIPRTP;
+      }
       failed |= (makemap(fd, NULL) == FAIL
-                 || makeset(fd, OPT_GLOBAL, false) == FAIL);
+                 || makeset(fd, flags, false) == FAIL);
     }
 
     if (!failed && view_session) {

src/nvim/option.c

@@ -5232,6 +5232,10 @@ int makeset(FILE *fd, int opt_flags, int local_only)
           continue;
         }
 
+        if ((opt_flags & OPT_SKIPRTP) && p->var == (char_u *)&p_rtp) {
+          continue;
+        }
+
         round = 2;
         if (p->indir != PV_NONE) {
           if (p->var == VAR_WIN) {

src/nvim/option.h

@@ -19,6 +19,9 @@ typedef enum {
   OPT_MODELINE = 8,   ///< Option in modeline.
   OPT_WINONLY  = 16,  ///< Only set window-local options.
   OPT_NOWIN    = 32,  ///< Don’t set window-local options.
+  OPT_ONECOLUMN = 64,  ///< list options one per line
+  OPT_NO_REDRAW = 128,  ///< ignore redraw flags on option
+  OPT_SKIPRTP = 256,  ///< "skiprtp" in 'sessionoptions'
 } OptionFlags;
 
 #ifdef INCLUDE_GENERATED_DECLARATIONS

src/nvim/option_defs.h

@@ -572,11 +572,12 @@ EXTERN char_u   *p_slm;         // 'selectmode'
 EXTERN char_u   *p_ssop;        // 'sessionoptions'
 EXTERN unsigned ssop_flags;
 # ifdef IN_OPTION_C
-// Also used for 'viewoptions'!
+// Also used for 'viewoptions'!  Keep in sync with SSOP_ flags.
 static char *(p_ssop_values[]) = {
   "buffers", "winpos", "resize", "winsize",
   "localoptions", "options", "help", "blank", "globals", "slash", "unix",
-  "sesdir", "curdir", "folds", "cursor", "tabpages", NULL
+  "sesdir", "curdir", "folds", "cursor", "tabpages", "terminal", "skiprtp",
+  NULL
 };
 # endif
 # define SSOP_BUFFERS           0x001
@@ -595,6 +596,8 @@ static char *(p_ssop_values[]) = {
 # define SSOP_FOLDS             0x2000
 # define SSOP_CURSOR            0x4000
 # define SSOP_TABPAGES          0x8000
+# define SSOP_TERMINAL          0x10000
+# define SSOP_SKIP_RTP          0x20000
 
 EXTERN char_u   *p_sh;          // 'shell'
 EXTERN char_u   *p_shcf;        // 'shellcmdflag'