fix(marks): handle switching buffer properly

src/nvim/ex_docmd.c

@@ -3379,6 +3379,7 @@ static linenr_T get_address(exarg_T *eap, char **ptr, cmd_addr_T addr_type, int
         fmark_T *fm = mark_get(curbuf, curwin, NULL, flag, *cmd);
         cmd++;
         if (fm != NULL && fm->fnum != curbuf->handle) {
+          (void)mark_move_to(fm, 0);
           // Jumped to another file.
           lnum = curwin->w_cursor.lnum;
         } else {

src/nvim/mark.c

@@ -520,7 +520,7 @@ static MarkMoveRes switch_to_mark_buf(fmark_T *fm, bool pcmark_on_switch)
   if (fm->fnum != curbuf->b_fnum) {
     // Switch to another file.
     int getfile_flag = pcmark_on_switch ? GETF_SETMARK : 0;
-    bool res = buflist_getfile(fm->fnum, (linenr_T)1, getfile_flag, false) == OK;
+    bool res = buflist_getfile(fm->fnum, fm->mark.lnum, getfile_flag, false) == OK;
     return res == true ? kMarkSwitchedBuf : kMarkMoveFailed;
   }
   return 0;

test/functional/editor/jump_spec.lua

@@ -48,6 +48,48 @@ describe('jumplist', function()
     feed('<C-O>')
     eq(buf1, funcs.bufnr('%'))
   end)
+
+  it('<C-O> scrolls cursor halfway when switching buffer #25763', function()
+    write_file(fname1, ('foobar\n'):rep(100))
+    write_file(fname2, 'baz')
+
+    local screen = Screen.new(5, 25)
+    screen:attach()
+    command('set number')
+    command('edit '..fname1)
+    feed('35gg')
+    command('edit '..fname2)
+    feed('<C-O>')
+    screen:expect{grid=[[
+      {1: 24 }foobar  |
+      {1: 25 }foobar  |
+      {1: 26 }foobar  |
+      {1: 27 }foobar  |
+      {1: 28 }foobar  |
+      {1: 29 }foobar  |
+      {1: 30 }foobar  |
+      {1: 31 }foobar  |
+      {1: 32 }foobar  |
+      {1: 33 }foobar  |
+      {1: 34 }foobar  |
+      {1: 35 }^foobar  |
+      {1: 36 }foobar  |
+      {1: 37 }foobar  |
+      {1: 38 }foobar  |
+      {1: 39 }foobar  |
+      {1: 40 }foobar  |
+      {1: 41 }foobar  |
+      {1: 42 }foobar  |
+      {1: 43 }foobar  |
+      {1: 44 }foobar  |
+      {1: 45 }foobar  |
+      {1: 46 }foobar  |
+      {1: 47 }foobar  |
+                  |
+    ]], attr_ids={
+      [1] = {foreground = Screen.colors.Brown};
+    }}
+  end)
 end)
 
 describe("jumpoptions=stack behaves like 'tagstack'", function()

test/functional/editor/mark_spec.lua

@@ -24,7 +24,6 @@ describe('named marks', function()
     os.remove(file2)
   end)
 
-
   it("can be set", function()
     command("edit " .. file1)
     command("mark a")
@@ -147,6 +146,20 @@ describe('named marks', function()
     eq({2, 2}, cursor())
   end)
 
+  it("can move to them using :'", function()
+    command("args " .. file1 .. " " .. file2)
+    feed("j")
+    feed("ma")
+    feed("G")
+    command("'a")
+    eq({2, 0}, cursor())
+    feed("mA")
+    command("next")
+    command("'A")
+    eq(1, meths.get_current_buf().id)
+    eq({2, 0}, cursor())
+  end)
+
   it("errors when it can't find the buffer", function()
     command("args " .. file1 .. " " .. file2)
     feed("mA")