revert: "shada/context: fully remove jumplist duplicates #10898" (#21874)

This reverts commit 8b8ecf44f2cda43bbd710ec22ef99439b71888cd.
It is causing performance problems on exit.
Fix #21082.

2 files changed, 17 insertions, 19 deletions

diff --git a/src/nvim/mark.c b/src/nvim/mark.c
index a76472230d..f1a1f25e6c 100644
--- a/src/nvim/mark.c
+++ b/src/nvim/mark.c
@@ -1380,18 +1380,21 @@ void mark_col_adjust(linenr_T lnum, colnr_T mincol, linenr_T lnum_amount, long c
 
 // When deleting lines, this may create duplicate marks in the
 // jumplist. They will be removed here for the specified window.
-// When "checktail" is true, removes tail jump if it matches current position.
-void cleanup_jumplist(win_T *wp, bool checktail)
+// When "loadfiles" is true first ensure entries have the "fnum" field set
+// (this may be a bit slow).
+void cleanup_jumplist(win_T *wp, bool loadfiles)
 {
   int i;
 
-  // Load all the files from the jump list. This is
-  // needed to properly clean up duplicate entries, but will take some
-  // time.
-  for (i = 0; i < wp->w_jumplistlen; i++) {
-    if ((wp->w_jumplist[i].fmark.fnum == 0)
-        && (wp->w_jumplist[i].fmark.mark.lnum != 0)) {
-      fname2fnum(&wp->w_jumplist[i]);
+  if (loadfiles) {
+    // If specified, load all the files from the jump list. This is
+    // needed to properly clean up duplicate entries, but will take some
+    // time.
+    for (i = 0; i < wp->w_jumplistlen; i++) {
+      if ((wp->w_jumplist[i].fmark.fnum == 0)
+          && (wp->w_jumplist[i].fmark.mark.lnum != 0)) {
+        fname2fnum(&wp->w_jumplist[i]);
+      }
     }
   }
 
@@ -1439,8 +1442,8 @@ void cleanup_jumplist(win_T *wp, bool checktail)
 
   // When pointer is below last jump, remove the jump if it matches the current
   // line.  This avoids useless/phantom jumps. #9805
-  if (checktail && wp->w_jumplistlen
-      && wp->w_jumplistidx == wp->w_jumplistlen) {
+  if (loadfiles  // otherwise (i.e.: Shada), last entry should be kept
+      && wp->w_jumplistlen && wp->w_jumplistidx == wp->w_jumplistlen) {
     const xfmark_T *fm_last = &wp->w_jumplist[wp->w_jumplistlen - 1];
     if (fm_last->fmark.fnum == curbuf->b_fnum
         && fm_last->fmark.mark.lnum == wp->w_cursor.lnum) {
diff --git a/src/nvim/shada.c b/src/nvim/shada.c
index 95151936c1..90a01aaf97 100644
--- a/src/nvim/shada.c
+++ b/src/nvim/shada.c
@@ -2667,8 +2667,6 @@ static ShaDaWriteResult shada_write(ShaDaWriteDef *const sd_writer, ShaDaReadDef
   }
 
   // Initialize jump list
-  setpcmark();
-  cleanup_jumplist(curwin, false);
   wms->jumps_size = shada_init_jumps(wms->jumps, &removable_bufs);
 
   const bool search_highlighted = !(no_hlsearch
@@ -4038,13 +4036,11 @@ static bool shada_removable(const char *name)
 static inline size_t shada_init_jumps(PossiblyFreedShadaEntry *jumps,
                                       khash_t(bufset) *const removable_bufs)
 {
-  if (!curwin->w_jumplistlen) {
-    return 0;
-  }
-
+  // Initialize jump list
   size_t jumps_size = 0;
   const void *jump_iter = NULL;
-
+  setpcmark();
+  cleanup_jumplist(curwin, false);
   do {
     xfmark_T fm;
     jump_iter = mark_jumplist_iter(jump_iter, curwin, &fm);
@@ -4117,7 +4113,6 @@ void shada_encode_jumps(msgpack_sbuffer *const sbuf)
   khash_t(bufset) removable_bufs = KHASH_EMPTY_TABLE(bufset);
   find_removable_bufs(&removable_bufs);
   PossiblyFreedShadaEntry jumps[JUMPLISTSIZE];
-  cleanup_jumplist(curwin, true);
   size_t jumps_size = shada_init_jumps(jumps, &removable_bufs);
   msgpack_packer packer;
   msgpack_packer_init(&packer, sbuf, msgpack_sbuffer_write);