viminfo: First version of ShaDa file dumping

What works:

1. ShaDa file dumping: header, registers, jump list, history, search patterns,
   substitute strings, variables.
2. ShaDa file reading: registers, global marks, variables.

Most was not tested.

TODO:

1. Merging.
2. Reading history, local marks, jump and buffer lists.
3. Documentation update.
4. Converting some data from &encoding.
5. Safer variant of dumping viminfo (dump to temporary file then rename).
6. Removing old viminfo code (currently masked with `#if 0` in a ShaDa file for
   reference).

34 files changed, 4361 insertions, 1816 deletions

diff --git a/src/nvim/api/private/helpers.h b/src/nvim/api/private/helpers.h
index f29deb53f9..a0f14ac7a4 100644
--- a/src/nvim/api/private/helpers.h
+++ b/src/nvim/api/private/helpers.h
@@ -69,6 +69,8 @@
 #define ADD(array, item)                                                      \
   kv_push(Object, array, item)
 
+#define STATIC_CSTR_AS_STRING(s) ((String) {.data = s, .size = sizeof(s) - 1})
+
 // Helpers used by the generated msgpack-rpc api wrappers
 #define api_init_boolean
 #define api_init_integer
diff --git a/src/nvim/auevents.lua b/src/nvim/auevents.lua
index af801c6f1a..3d8a75febd 100644
--- a/src/nvim/auevents.lua
+++ b/src/nvim/auevents.lua
@@ -84,7 +84,7 @@ return {
     'User',                   -- user defined autocommand
     'VimEnter',               -- after starting Vim
     'VimLeave',               -- before exiting Vim
-    'VimLeavePre',            -- before exiting Vim and writing .viminfo
+    'VimLeavePre',            -- before exiting Vim and writing ShaDa file
     'VimResized',             -- after Vim window was resized
     'WinEnter',               -- after entering a window
     'WinLeave',               -- before leaving a window
diff --git a/src/nvim/buffer.c b/src/nvim/buffer.c
index b212e75283..5ebeec1b70 100644
--- a/src/nvim/buffer.c
+++ b/src/nvim/buffer.c
@@ -73,6 +73,7 @@
 #include "nvim/undo.h"
 #include "nvim/version.h"
 #include "nvim/window.h"
+#include "nvim/shada.h"
 #include "nvim/os/os.h"
 #include "nvim/os/time.h"
 #include "nvim/os/input.h"
@@ -555,6 +556,12 @@ static void free_buffer(buf_T *buf)
   free_buffer_stuff(buf, TRUE);
   unref_var_dict(buf->b_vars);
   aubuflocal_remove(buf);
+  free_fmark(buf->b_last_cursor);
+  free_fmark(buf->b_last_insert);
+  free_fmark(buf->b_last_change);
+  for (size_t i = 0; i < NMARKS; i++) {
+    free_fmark(buf->b_namedm[i]);
+  }
   if (autocmd_busy) {
     // Do not free the buffer structure while autocommands are executing,
     // it's still needed. Free it when autocmd_busy is reset.
@@ -4164,93 +4171,6 @@ chk_modeline (
   return retval;
 }
 
-int read_viminfo_bufferlist(vir_T *virp, int writing)
-{
-  char_u      *tab;
-  linenr_T lnum;
-  colnr_T col;
-  buf_T       *buf;
-  char_u      *sfname;
-  char_u      *xline;
-
-  /* Handle long line and escaped characters. */
-  xline = viminfo_readstring(virp, 1, FALSE);
-
-  /* don't read in if there are files on the command-line or if writing: */
-  if (xline != NULL && !writing && ARGCOUNT == 0
-      && find_viminfo_parameter('%') != NULL) {
-    /* Format is: <fname> Tab <lnum> Tab <col>.
-     * Watch out for a Tab in the file name, work from the end. */
-    lnum = 0;
-    col = 0;
-    tab = vim_strrchr(xline, '\t');
-    if (tab != NULL) {
-      *tab++ = '\0';
-      col = (colnr_T)atoi((char *)tab);
-      tab = vim_strrchr(xline, '\t');
-      if (tab != NULL) {
-        *tab++ = '\0';
-        lnum = atol((char *)tab);
-      }
-    }
-
-    /* Expand "~/" in the file name at "line + 1" to a full path.
-     * Then try shortening it by comparing with the current directory */
-    expand_env(xline, NameBuff, MAXPATHL);
-    sfname = path_shorten_fname_if_possible(NameBuff);
-
-    buf = buflist_new(NameBuff, sfname, (linenr_T)0, BLN_LISTED);
-    if (buf != NULL) {          /* just in case... */
-      buf->b_last_cursor.lnum = lnum;
-      buf->b_last_cursor.col = col;
-      buflist_setfpos(buf, curwin, lnum, col, FALSE);
-    }
-  }
-  xfree(xline);
-
-  return viminfo_readline(virp);
-}
-
-void write_viminfo_bufferlist(FILE *fp)
-{
-  char_u      *line;
-  int max_buffers;
-
-  if (find_viminfo_parameter('%') == NULL)
-    return;
-
-  /* Without a number -1 is returned: do all buffers. */
-  max_buffers = get_viminfo_parameter('%');
-
-  /* Allocate room for the file name, lnum and col. */
-#define LINE_BUF_LEN (MAXPATHL + 40)
-  line = xmalloc(LINE_BUF_LEN);
-
-  FOR_ALL_TAB_WINDOWS(tp, win) {
-    set_last_cursor(win);
-  }
-
-  fputs(_("\n# Buffer list:\n"), fp);
-  FOR_ALL_BUFFERS(buf) {
-    if (buf->b_fname == NULL
-        || !buf->b_p_bl
-        || bt_quickfix(buf)
-        || removable(buf->b_ffname))
-      continue;
-
-    if (max_buffers-- == 0)
-      break;
-    putc('%', fp);
-    home_replace(NULL, buf->b_ffname, line, MAXPATHL, TRUE);
-    vim_snprintf_add((char *)line, LINE_BUF_LEN, "\t%" PRId64 "\t%d",
-        (int64_t)buf->b_last_cursor.lnum,
-        buf->b_last_cursor.col);
-    viminfo_writestring(fp, line);
-  }
-  xfree(line);
-}
-
-
 /*
  * Return special buffer name.
  * Returns NULL when the buffer has a normal file name.
diff --git a/src/nvim/buffer_defs.h b/src/nvim/buffer_defs.h
index 98fbef9c87..6fbdea2c62 100644
--- a/src/nvim/buffer_defs.h
+++ b/src/nvim/buffer_defs.h
@@ -327,15 +327,6 @@ typedef struct {
   bool vc_fail;                 /* fail for invalid char, don't use '?' */
 } vimconv_T;
 
-/*
- * Structure used for reading from the viminfo file.
- */
-typedef struct {
-  char_u      *vir_line;        /* text of the current line */
-  FILE        *vir_fd;          /* file descriptor */
-  vimconv_T vir_conv;           /* encoding conversion */
-} vir_T;
-
 #define CONV_NONE               0
 #define CONV_TO_UTF8            1
 #define CONV_9_TO_UTF8          2
@@ -515,16 +506,16 @@ struct file_buffer {
   uint64_t b_orig_size;         /* size of original file in bytes */
   int b_orig_mode;              /* mode of original file */
 
-  pos_T b_namedm[NMARKS];         /* current named marks (mark.c) */
+  fmark_T b_namedm[NMARKS];     /* current named marks (mark.c) */
 
   /* These variables are set when VIsual_active becomes FALSE */
   visualinfo_T b_visual;
   int b_visual_mode_eval;            /* b_visual.vi_mode for visualmode() */
 
-  pos_T b_last_cursor;          /* cursor position when last unloading this
+  fmark_T b_last_cursor;        /* cursor position when last unloading this
                                    buffer */
-  pos_T b_last_insert;          /* where Insert mode was left */
-  pos_T b_last_change;          /* position of last change: '. mark */
+  fmark_T b_last_insert;        /* where Insert mode was left */
+  fmark_T b_last_change;        /* position of last change: '. mark */
 
   /*
    * the changelist contains old change positions
@@ -553,7 +544,7 @@ struct file_buffer {
   pos_T b_op_start_orig;  // used for Insstart_orig
   pos_T b_op_end;
 
-  bool b_marks_read;            /* Have we read viminfo marks yet? */
+  bool b_marks_read;            /* Have we read ShaDa marks yet? */
 
   /*
    * The following only used in undo.c.
diff --git a/src/nvim/edit.c b/src/nvim/edit.c
index 427623e052..310191ba06 100644
--- a/src/nvim/edit.c
+++ b/src/nvim/edit.c
@@ -60,6 +60,7 @@
 #include "nvim/undo.h"
 #include "nvim/window.h"
 #include "nvim/event/loop.h"
+#include "nvim/mark.h"
 #include "nvim/os/input.h"
 #include "nvim/os/time.h"
 
@@ -6991,8 +6992,9 @@ ins_esc (
     curwin->w_set_curswant = TRUE;
 
   /* Remember the last Insert position in the '^ mark. */
-  if (!cmdmod.keepjumps)
-    curbuf->b_last_insert = curwin->w_cursor;
+  if (!cmdmod.keepjumps) {
+    RESET_FMARK(&curbuf->b_last_insert, curwin->w_cursor, curbuf->b_fnum);
+  }
 
   /*
    * The cursor should end up on the last inserted character.
diff --git a/src/nvim/eval.c b/src/nvim/eval.c
index 65afd19bbe..5a7d4702d2 100644
--- a/src/nvim/eval.c
+++ b/src/nvim/eval.c
@@ -354,7 +354,7 @@ typedef struct {
 typedef enum {
   VAR_FLAVOUR_DEFAULT,          /* doesn't start with uppercase */
   VAR_FLAVOUR_SESSION,          /* starts with uppercase, some lower */
-  VAR_FLAVOUR_VIMINFO           /* all uppercase */
+  VAR_FLAVOUR_SHADA             /* all uppercase */
 } var_flavour_T;
 
 /* values for vv_flags: */
@@ -10482,6 +10482,7 @@ static void f_has(typval_T *argvars, typval_T *rettv)
     "scrollbind",
     "showcmd",
     "cmdline_info",
+    "shada",
     "signs",
     "smartindent",
     "startuptime",
@@ -10498,7 +10499,6 @@ static void f_has(typval_T *argvars, typval_T *rettv)
     "title",
     "user-commands",        /* was accidentally included in 5.4 */
     "user_commands",
-    "viminfo",
     "vertsplit",
     "virtualedit",
     "visual",
@@ -20712,107 +20712,62 @@ static var_flavour_T var_flavour(char_u *varname)
     while (*(++p))
       if (ASCII_ISLOWER(*p))
         return VAR_FLAVOUR_SESSION;
-    return VAR_FLAVOUR_VIMINFO;
+    return VAR_FLAVOUR_SHADA;
   } else
     return VAR_FLAVOUR_DEFAULT;
 }
 
-/*
- * Restore global vars that start with a capital from the viminfo file
- */
-int read_viminfo_varlist(vir_T *virp, int writing)
-{
-  char_u      *tab;
-  int type = VAR_NUMBER;
-  typval_T tv;
-
-  if (!writing && (find_viminfo_parameter('!') != NULL)) {
-    tab = vim_strchr(virp->vir_line + 1, '\t');
-    if (tab != NULL) {
-      *tab++ = NUL;            /* isolate the variable name */
-      switch (*tab) {
-      case 'S': type = VAR_STRING; break;
-      case 'F': type = VAR_FLOAT; break;
-      case 'D': type = VAR_DICT; break;
-      case 'L': type = VAR_LIST; break;
-      }
-
-      tab = vim_strchr(tab, '\t');
-      if (tab != NULL) {
-        tv.v_type = type;
-        if (type == VAR_STRING || type == VAR_DICT || type == VAR_LIST)
-          tv.vval.v_string = viminfo_readstring(virp,
-              (int)(tab - virp->vir_line + 1), TRUE);
-        else if (type == VAR_FLOAT)
-          (void)string2float(tab + 1, &tv.vval.v_float);
-        else
-          tv.vval.v_number = atol((char *)tab + 1);
-        if (type == VAR_DICT || type == VAR_LIST) {
-          typval_T *etv = eval_expr(tv.vval.v_string, NULL);
-
-          if (etv == NULL)
-            /* Failed to parse back the dict or list, use it as a
-             * string. */
-            tv.v_type = VAR_STRING;
-          else {
-            xfree(tv.vval.v_string);
-            tv = *etv;
-            xfree(etv);
-          }
-        }
-
-        set_var(virp->vir_line + 1, &tv, FALSE);
-
-        if (tv.v_type == VAR_STRING)
-          xfree(tv.vval.v_string);
-        else if (tv.v_type == VAR_DICT || tv.v_type == VAR_LIST)
-          clear_tv(&tv);
-      }
+/// Iterate over global variables
+///
+/// @warning No modifications to global variable dictionary must be performed 
+///          while iteration is in progress.
+///
+/// @param[in]   iter   Iterator. Pass NULL to start iteration.
+/// @param[out]  name   Variable name.
+/// @param[out]  rettv  Variable value.
+///
+/// @return Pointer that needs to be passed to next `var_shada_iter` invocation 
+///         or NULL to indicate that iteration is over.
+const void *var_shada_iter(const void *const iter, const char **const name,
+                           typval_T *rettv)
+  FUNC_ATTR_PURE FUNC_ATTR_WARN_UNUSED_RESULT FUNC_ATTR_NONNULL_ARG(2, 3)
+{
+  const hashitem_T *hi;
+  const hashitem_T *hifirst = globvarht.ht_array;
+  const size_t hinum = (size_t) globvarht.ht_mask + 1;
+  *name = NULL;
+  if (iter == NULL) {
+    hi = globvarht.ht_array;
+    while ((HASHITEM_EMPTY(hi)
+            || var_flavour(HI2DI(hi)->di_key) != VAR_FLAVOUR_SHADA)
+           && (size_t) (hi - hifirst) < hinum) {
+      hi++;
+    }
+    if (HASHITEM_EMPTY(hi)
+        || var_flavour(HI2DI(hi)->di_key) != VAR_FLAVOUR_SHADA) {
+      *rettv = (typval_T) {.v_type = VAR_UNKNOWN};
+      return NULL;
     }
+  } else {
+    hi = (const hashitem_T *) iter;
   }
-
-  return viminfo_readline(virp);
+  *name = (char *) HI2DI(hi)->di_key;
+  copy_tv(&(HI2DI(hi)->di_tv), rettv);
+  while ((size_t) (++hi - hifirst) < hinum) {
+    if (!HASHITEM_EMPTY(hi)
+        && var_flavour(HI2DI(hi)->di_key) == VAR_FLAVOUR_SHADA) {
+      return hi;
+    }
+  }
+  return NULL;
 }
 
-/*
- * Write global vars that start with a capital to the viminfo file
- */
-void write_viminfo_varlist(FILE *fp)
+void var_set_global(const char *const name, typval_T vartv)
 {
-  hashitem_T  *hi;
-  dictitem_T  *this_var;
-  int todo;
-  char        *s;
-  char_u      *p;
-
-  if (find_viminfo_parameter('!') == NULL)
-    return;
-
-  fputs(_("\n# global variables:\n"), fp);
-
-  todo = (int)globvarht.ht_used;
-  for (hi = globvarht.ht_array; todo > 0; ++hi) {
-    if (!HASHITEM_EMPTY(hi)) {
-      --todo;
-      this_var = HI2DI(hi);
-      if (var_flavour(this_var->di_key) == VAR_FLAVOUR_VIMINFO) {
-        switch (this_var->di_tv.v_type) {
-        case VAR_STRING: s = "STR"; break;
-        case VAR_NUMBER: s = "NUM"; break;
-        case VAR_FLOAT:  s = "FLO"; break;
-        case VAR_DICT:   s = "DIC"; break;
-        case VAR_LIST:   s = "LIS"; break;
-        default: continue;
-        }
-        fprintf(fp, "!%s\t%s\t", this_var->di_key, s);
-        p = (char_u *) echo_string(&this_var->di_tv, NULL);
-        if (p != NULL) {
-          viminfo_writestring(fp, p);
-        }
-        xfree(p);
-      }
-    }
-  }
+  funccall_T *const saved_current_funccal = current_funccal;
+  current_funccal = NULL;
+  set_var((char_u *) name, &vartv, false);
+  current_funccal = saved_current_funccal;
 }
 
 int store_session_globals(FILE *fd)
diff --git a/src/nvim/ex_cmds.c b/src/nvim/ex_cmds.c
index 81abf2fa63..262150a8c0 100644
--- a/src/nvim/ex_cmds.c
+++ b/src/nvim/ex_cmds.c
@@ -67,6 +67,9 @@
 #include "nvim/os/os.h"
 #include "nvim/os/shell.h"
 #include "nvim/os/input.h"
+#include "nvim/os/time.h"
+#include "nvim/api/private/defs.h"
+#include "nvim/api/private/helpers.h"
 
 /*
  * Struct to hold the sign properties.
@@ -1391,550 +1394,6 @@ void append_redir(char_u *buf, int buflen, char_u *opt, char_u *fname)
         (char *)opt, (char *)fname);
 }
 
-
-static int viminfo_errcnt;
-
-static int no_viminfo(void)
-{
-  /* "vim -i NONE" does not read or write a viminfo file */
-  return use_viminfo != NULL && STRCMP(use_viminfo, "NONE") == 0;
-}
-
-/*
- * Report an error for reading a viminfo file.
- * Count the number of errors.	When there are more than 10, return TRUE.
- */
-int viminfo_error(char *errnum, char *message, char_u *line)
-{
-  vim_snprintf((char *)IObuff, IOSIZE, _("%sviminfo: %s in line: "),
-      errnum, message);
-  STRNCAT(IObuff, line, IOSIZE - STRLEN(IObuff) - 1);
-  if (IObuff[STRLEN(IObuff) - 1] == '\n')
-    IObuff[STRLEN(IObuff) - 1] = NUL;
-  emsg(IObuff);
-  if (++viminfo_errcnt >= 10) {
-    EMSG(_("E136: viminfo: Too many errors, skipping rest of file"));
-    return TRUE;
-  }
-  return FALSE;
-}
-
-/*
- * read_viminfo() -- Read the viminfo file.  Registers etc. which are already
- * set are not over-written unless "flags" includes VIF_FORCEIT. -- webb
- */
-int 
-read_viminfo (
-    char_u *file,          /* file name or NULL to use default name */
-    int flags                  /* VIF_WANT_INFO et al. */
-)
-{
-  FILE        *fp;
-  char_u      *fname;
-
-  if (no_viminfo())
-    return FAIL;
-
-  fname = viminfo_filename(file);       /* get file name in allocated buffer */
-  fp = mch_fopen((char *)fname, READBIN);
-
-  if (p_verbose > 0) {
-    verbose_enter();
-    smsg(_("Reading viminfo file \"%s\"%s%s%s"),
-        fname,
-        (flags & VIF_WANT_INFO) ? _(" info") : "",
-        (flags & VIF_WANT_MARKS) ? _(" marks") : "",
-        (flags & VIF_GET_OLDFILES) ? _(" oldfiles") : "",
-        fp == NULL ? _(" FAILED") : "");
-    verbose_leave();
-  }
-
-  xfree(fname);
-  if (fp == NULL)
-    return FAIL;
-
-  viminfo_errcnt = 0;
-  do_viminfo(fp, NULL, flags);
-
-  fclose(fp);
-  return OK;
-}
-
-/*
- * Write the viminfo file.  The old one is read in first so that effectively a
- * merge of current info and old info is done.  This allows multiple vims to
- * run simultaneously, without losing any marks etc.
- * If "forceit" is TRUE, then the old file is not read in, and only internal
- * info is written to the file.
- */
-void write_viminfo(char_u *file, int forceit)
-{
-  char_u      *fname;
-  FILE        *fp_in = NULL;    /* input viminfo file, if any */
-  FILE        *fp_out = NULL;   /* output viminfo file */
-  char_u      *tempname = NULL;         /* name of temp viminfo file */
-  char_u      *wp;
-#if defined(UNIX)
-  mode_t umask_save;
-#endif
-
-  if (no_viminfo())
-    return;
-
-  fname = viminfo_filename(file);       /* may set to default if NULL */
-
-  fp_in = mch_fopen((char *)fname, READBIN);
-  if (fp_in == NULL) {
-    /* if it does exist, but we can't read it, don't try writing */
-    if (os_file_exists(fname))
-      goto end;
-#if defined(UNIX)
-    /*
-     * For Unix we create the .viminfo non-accessible for others,
-     * because it may contain text from non-accessible documents.
-     */
-    umask_save = umask(077);
-#endif
-    fp_out = mch_fopen((char *)fname, WRITEBIN);
-#if defined(UNIX)
-    (void)umask(umask_save);
-#endif
-  } else {
-    /*
-     * There is an existing viminfo file.  Create a temporary file to
-     * write the new viminfo into, in the same directory as the
-     * existing viminfo file, which will be renamed later.
-     */
-#ifdef UNIX
-    /*
-     * For Unix we check the owner of the file.  It's not very nice to
-     * overwrite a user's viminfo file after a "su root", with a
-     * viminfo file that the user can't read.
-     */
-
-    FileInfo old_info;  // FileInfo of existing viminfo file
-    if (os_fileinfo((char *)fname, &old_info)
-        && getuid() != ROOT_UID
-        && !(old_info.stat.st_uid == getuid()
-             ? (old_info.stat.st_mode & 0200)
-             : (old_info.stat.st_gid == getgid()
-                ? (old_info.stat.st_mode & 0020)
-                : (old_info.stat.st_mode & 0002)))) {
-      int tt = msg_didany;
-
-      /* avoid a wait_return for this message, it's annoying */
-      EMSG2(_("E137: Viminfo file is not writable: %s"), fname);
-      msg_didany = tt;
-      fclose(fp_in);
-      goto end;
-    }
-#endif
-
-    // Make tempname
-    tempname = (char_u *)modname((char *)fname, ".tmp", FALSE);
-    if (tempname != NULL) {
-      /*
-       * Check if tempfile already exists.  Never overwrite an
-       * existing file!
-       */
-      if (os_file_exists(tempname)) {
-        /*
-         * Try another name.  Change one character, just before
-         * the extension.
-         */
-        wp = tempname + STRLEN(tempname) - 5;
-        if (wp < path_tail(tempname))                 /* empty file name? */
-          wp = path_tail(tempname);
-        for (*wp = 'z'; os_file_exists(tempname); --*wp) {
-          /*
-           * They all exist?  Must be something wrong! Don't
-           * write the viminfo file then.
-           */
-          if (*wp == 'a') {
-            xfree(tempname);
-            tempname = NULL;
-            break;
-          }
-        }
-      }
-    }
-
-    if (tempname != NULL) {
-      int fd;
-
-      /* Use os_open() to be able to use O_NOFOLLOW and set file
-       * protection:
-       * Unix: same as original file, but strip s-bit.  Reset umask to
-       * avoid it getting in the way.
-       * Others: r&w for user only. */
-# ifdef UNIX
-      umask_save = umask(0);
-      fd = os_open((char *)tempname,
-          O_CREAT|O_EXCL|O_WRONLY|O_NOFOLLOW,
-          (int)((old_info.stat.st_mode & 0777) | 0600));
-      (void)umask(umask_save);
-# else
-      fd = os_open((char *)tempname,
-          O_CREAT|O_EXCL|O_WRONLY|O_NOFOLLOW, 0600);
-# endif
-      if (fd < 0)
-        fp_out = NULL;
-      else
-        fp_out = fdopen(fd, WRITEBIN);
-
-      /*
-       * If we can't create in the same directory, try creating a
-       * "normal" temp file.
-       */
-      if (fp_out == NULL) {
-        xfree(tempname);
-        if ((tempname = vim_tempname()) != NULL)
-          fp_out = mch_fopen((char *)tempname, WRITEBIN);
-      }
-
-#ifdef UNIX
-      /*
-       * Make sure the owner can read/write it.  This only works for
-       * root.
-       */
-      if (fp_out != NULL) {
-        os_fchown(fileno(fp_out), old_info.stat.st_uid, old_info.stat.st_gid);
-      }
-#endif
-    }
-  }
-
-  /*
-   * Check if the new viminfo file can be written to.
-   */
-  if (fp_out == NULL) {
-    EMSG2(_("E138: Can't write viminfo file %s!"),
-        (fp_in == NULL || tempname == NULL) ? fname : tempname);
-    if (fp_in != NULL)
-      fclose(fp_in);
-    goto end;
-  }
-
-  if (p_verbose > 0) {
-    verbose_enter();
-    smsg(_("Writing viminfo file \"%s\""), fname);
-    verbose_leave();
-  }
-
-  viminfo_errcnt = 0;
-  do_viminfo(fp_in, fp_out, forceit ? 0 : (VIF_WANT_INFO | VIF_WANT_MARKS));
-
-  fclose(fp_out);           /* errors are ignored !? */
-  if (fp_in != NULL) {
-    fclose(fp_in);
-
-    /* In case of an error keep the original viminfo file. Otherwise
-     * rename the newly written file. Give an error if that fails. */
-    if (viminfo_errcnt == 0 && vim_rename(tempname, fname) == -1) {
-      viminfo_errcnt++;
-      EMSG2(_("E886: Can't rename viminfo file to %s!"), fname);
-    }
-    if (viminfo_errcnt > 0) {
-      os_remove((char *)tempname);
-    }
-  }
-
-end:
-  xfree(fname);
-  xfree(tempname);
-}
-
-/*
- * Get the viminfo file name to use.
- * If "file" is given and not empty, use it (has already been expanded by
- * cmdline functions).
- * Otherwise use "-i file_name", value from 'viminfo' or the default, and
- * expand environment variables.
- * Returns an allocated string.
- */
-static char_u *viminfo_filename(char_u *file)
-{
-  if (file == NULL || *file == NUL) {
-    if (use_viminfo != NULL)
-      file = use_viminfo;
-    else if ((file = find_viminfo_parameter('n')) == NULL || *file == NUL) {
-#ifdef VIMINFO_FILE2
-      // don't use $HOME when not defined (turned into "c:/"!).
-      if (!os_env_exists("HOME")) {
-        // don't use $VIM when not available.
-        expand_env((char_u *)"$VIM", NameBuff, MAXPATHL);
-        if (STRCMP("$VIM", NameBuff) != 0)          /* $VIM was expanded */
-          file = (char_u *)VIMINFO_FILE2;
-        else
-          file = (char_u *)VIMINFO_FILE;
-      } else
-#endif
-      file = (char_u *)VIMINFO_FILE;
-    }
-    expand_env(file, NameBuff, MAXPATHL);
-    file = NameBuff;
-  }
-  return vim_strsave(file);
-}
-
-/*
- * do_viminfo() -- Should only be called from read_viminfo() & write_viminfo().
- */
-static void do_viminfo(FILE *fp_in, FILE *fp_out, int flags)
-{
-  int count = 0;
-  int eof = FALSE;
-  vir_T vir;
-  int merge = FALSE;
-
-  vir.vir_line = xmalloc(LSIZE);
-  vir.vir_fd = fp_in;
-  vir.vir_conv.vc_type = CONV_NONE;
-
-  if (fp_in != NULL) {
-    if (flags & VIF_WANT_INFO) {
-      eof = read_viminfo_up_to_marks(&vir,
-          flags & VIF_FORCEIT, fp_out != NULL);
-      merge = TRUE;
-    } else if (flags != 0)
-      /* Skip info, find start of marks */
-      while (!(eof = viminfo_readline(&vir))
-             && vir.vir_line[0] != '>')
-        ;
-  }
-  if (fp_out != NULL) {
-    /* Write the info: */
-    fprintf(fp_out, _("# This viminfo file was generated by Nvim %s.\n"),
-        mediumVersion);
-    fputs(_("# You may edit it if you're careful!\n\n"), fp_out);
-    fputs(_("# Value of 'encoding' when this file was written\n"), fp_out);
-    fprintf(fp_out, "*encoding=%s\n\n", p_enc);
-    write_viminfo_search_pattern(fp_out);
-    write_viminfo_sub_string(fp_out);
-    write_viminfo_history(fp_out, merge);
-    write_viminfo_registers(fp_out);
-    write_viminfo_varlist(fp_out);
-    write_viminfo_filemarks(fp_out);
-    write_viminfo_bufferlist(fp_out);
-    count = write_viminfo_marks(fp_out);
-  }
-  if (fp_in != NULL
-      && (flags & (VIF_WANT_MARKS | VIF_GET_OLDFILES | VIF_FORCEIT)))
-    copy_viminfo_marks(&vir, fp_out, count, eof, flags);
-
-  xfree(vir.vir_line);
-  if (vir.vir_conv.vc_type != CONV_NONE)
-    convert_setup(&vir.vir_conv, NULL, NULL);
-}
-
-/*
- * read_viminfo_up_to_marks() -- Only called from do_viminfo().  Reads in the
- * first part of the viminfo file which contains everything but the marks that
- * are local to a file.  Returns TRUE when end-of-file is reached. -- webb
- */
-static int read_viminfo_up_to_marks(vir_T *virp, int forceit, int writing)
-{
-  int eof;
-
-  prepare_viminfo_history(forceit ? 9999 : 0, writing);
-  eof = viminfo_readline(virp);
-  while (!eof && virp->vir_line[0] != '>') {
-    switch (virp->vir_line[0]) {
-    /* Characters reserved for future expansion, ignored now */
-    case '+':         /* "+40 /path/dir file", for running vim without args */
-    case '|':         /* to be defined */
-    case '^':         /* to be defined */
-    case '<':         /* long line - ignored */
-    /* A comment or empty line. */
-    case NUL:
-    case '\r':
-    case '\n':
-    case '#':
-      eof = viminfo_readline(virp);
-      break;
-    case '*':         /* "*encoding=value" */
-      eof = viminfo_encoding(virp);
-      break;
-    case '!':         /* global variable */
-      eof = read_viminfo_varlist(virp, writing);
-      break;
-    case '%':         /* entry for buffer list */
-      eof = read_viminfo_bufferlist(virp, writing);
-      break;
-    case '"':
-      eof = read_viminfo_register(virp, forceit);
-      break;
-    case '/':               /* Search string */
-    case '&':               /* Substitute search string */
-    case '~':               /* Last search string, followed by '/' or '&' */
-      eof = read_viminfo_search_pattern(virp, forceit);
-      break;
-    case '$':
-      eof = read_viminfo_sub_string(virp, forceit);
-      break;</