clipboard: simplify handling of of put in visual mode.

When clipboard=unnamed and put over visual selection, reduces number of
provider calls from 6 to 2. Also add test.

src/nvim/edit.c

@@ -6762,7 +6762,7 @@ static void ins_reg(void)
       AppendCharToRedobuff(literally);
       AppendCharToRedobuff(regname);
 
-      do_put(regname, BACKWARD, 1L,
+      do_put(regname, NULL, BACKWARD, 1L,
           (literally == Ctrl_P ? PUT_FIXINDENT : 0) | PUT_CURSEND);
     } else if (insert_reg(regname, literally) == FAIL) {
       vim_beep();

src/nvim/ex_docmd.c

@@ -6515,7 +6515,7 @@ static void ex_put(exarg_T *eap)
     eap->forceit = TRUE;
   }
   curwin->w_cursor.lnum = eap->line2;
-  do_put(eap->regname, eap->forceit ? BACKWARD : FORWARD, 1L,
+  do_put(eap->regname, NULL, eap->forceit ? BACKWARD : FORWARD, 1L,
       PUT_LINE|PUT_CURSLINE);
 }
 

src/nvim/normal.c

@@ -1995,7 +1995,7 @@ do_mouse (
         if ((State & REPLACE_FLAG) && !yank_register_mline(regname))
           insert_reg(regname, true);
         else {
-          do_put(regname, BACKWARD, 1L, fixindent | PUT_CURSEND);
+          do_put(regname, NULL, BACKWARD, 1L, fixindent | PUT_CURSEND);
 
           /* Repeat it with CTRL-R CTRL-O r or CTRL-R CTRL-P r */
           AppendCharToRedobuff(Ctrl_R);
@@ -2280,7 +2280,7 @@ do_mouse (
      */
     if (restart_edit != 0)
       where_paste_started = curwin->w_cursor;
-    do_put(regname, dir, count, fixindent | PUT_CURSEND);
+    do_put(regname, NULL, dir, count, fixindent | PUT_CURSEND);
   }
   /*
    * Ctrl-Mouse click or double click in a quickfix window jumps to the
@@ -5085,7 +5085,7 @@ static void nv_brackets(cmdarg_T *cap)
         curwin->w_cursor = (dir == BACKWARD ? start : end);
       }
       prep_redo_cmd(cap);
-      do_put(regname, dir, cap->count1, PUT_FIXINDENT);
+      do_put(regname, NULL, dir, cap->count1, PUT_FIXINDENT);
       if (was_visual) {
         VIsual = start;
         curwin->w_cursor = end;
@@ -7221,7 +7221,7 @@ static void nv_join(cmdarg_T *cap)
 static void nv_put(cmdarg_T *cap)
 {
   int regname = 0;
-  void        *reg1 = NULL, *reg2 = NULL;
+  yankreg_T *savereg = NULL;
   bool empty = false;
   bool was_visual = false;
   int dir;
@@ -7252,11 +7252,9 @@ static void nv_put(cmdarg_T *cap)
       was_visual = true;
       regname = cap->oap->regname;
       if (regname == 0 || regname == '"'
-          || VIM_ISDIGIT(regname) || regname == '-'
-          ) {
-        /* The delete is going to overwrite the register we want to
-         * put, save it first. */
-        reg1 = get_register(regname, true);
+          || VIM_ISDIGIT(regname) || regname == '-') {
+        // The delete might overwrite the register we want to put, save it first
+        savereg = copy_register(regname);
       }
 
       /* Now delete the selected text. */
@@ -7270,13 +7268,6 @@ static void nv_put(cmdarg_T *cap)
       /* delete PUT_LINE_BACKWARD; */
       cap->oap->regname = regname;
 
-      if (reg1 != NULL) {
-        /* Delete probably changed the register we want to put, save
-         * it first. Then put back what was there before the delete. */
-        reg2 = get_register(regname, false);
-        put_register(regname, reg1);
-      }
-
       /* When deleted a linewise Visual area, put the register as
        * lines to avoid it joined with the next line.  When deletion was
        * characterwise, split a line when putting lines. */
@@ -7297,11 +7288,13 @@ static void nv_put(cmdarg_T *cap)
       /* May have been reset in do_put(). */
       VIsual_active = true;
     }
-    do_put(cap->oap->regname, dir, cap->count1, flags);
+    do_put(cap->oap->regname, savereg, dir, cap->count1, flags);
 
-    /* If a register was saved, put it back now. */
-    if (reg2 != NULL)
-      put_register(regname, reg2);
+    // If a register was saved, free it
+    if (savereg != NULL) {
+      free_register(savereg);
+      xfree(savereg);
+    }
 
     /* What to reselect with "gv"?  Selecting the just put text seems to
      * be the most useful, since the original text was removed. */

src/nvim/ops.c

@@ -800,46 +800,25 @@ static bool is_append_register(int regname)
   return ASCII_ISUPPER(regname);
 }
 
-/*
- * Obtain the contents of a "normal" register. The register is made empty.
- * The returned pointer has allocated memory, use put_register() later.
- */
-void *
-get_register (
-    int name,
-    int copy               /* make a copy, if FALSE make register empty. */
-) FUNC_ATTR_NONNULL_RET
+/// Returns a copy of contents in register `name`
+/// for use in do_put. Should be freed by caller.
+yankreg_T *copy_register(int name)
+  FUNC_ATTR_MALLOC
+  FUNC_ATTR_NONNULL_RET
 {
   yankreg_T *reg = get_yank_register(name, YREG_PASTE);
 
-  yankreg_T *tmpreg = xmalloc(sizeof(yankreg_T));
-  *tmpreg = *reg;
-  if (copy) {
-    if (tmpreg->y_size == 0) {
-      tmpreg->y_array = NULL;
-    } else {
-      tmpreg->y_array = xmalloc(tmpreg->y_size * sizeof(char_u *));
-      for (linenr_T i = 0; i < tmpreg->y_size; i++) {
-        tmpreg->y_array[i] = vim_strsave(reg->y_array[i]);
-      }
-    }
+  yankreg_T *copy = xmalloc(sizeof(yankreg_T));
+  *copy = *reg;
+  if (copy->y_size == 0) {
+    copy->y_array = NULL;
   } else {
-    reg->y_array = NULL;
+    copy->y_array = xcalloc(copy->y_size, sizeof(char_u *));
+    for (linenr_T i = 0; i < copy->y_size; i++) {
+      copy->y_array[i] = vim_strsave(reg->y_array[i]);
+    }
   }
-
-  return (void *)tmpreg;
-}
-
-/*
- * Put "tmpreg" into register "name".  Free any previous contents and "tmpreg".
- */
-void put_register(int name, void *tmpreg)
-{
-  yankreg_T *reg = get_yank_register(name, YREG_PUT);
-  free_register(reg);
-  *reg = *(yankreg_T *)tmpreg;
-  xfree(tmpreg);
-  set_clipboard(name, reg);
+  return copy;
 }
 
 /*
@@ -2299,11 +2278,12 @@ void clear_registers(void)
 
 #endif
 
-/*
- * Free contents of yankreg reg.
- * Called for normal freeing and in case of error.
- */
-static void free_register(yankreg_T *reg)
+
+ /// Free contents of yankreg `reg`.
+ /// Called for normal freeing and in case of error.
+ /// `reg` must not be NULL (but `reg->y_array` might be)
+void free_register(yankreg_T *reg)
+  FUNC_ATTR_NONNULL_ALL
 {
   if (reg->y_array != NULL) {
     long i;
@@ -2562,14 +2542,8 @@ static void yank_copy_line(yankreg_T *reg, struct block_def *bd, long y_idx)
  * "flags": PUT_FIXINDENT	make indent look nice
  *	    PUT_CURSEND		leave cursor after end of new text
  *	    PUT_LINE		force linewise put (":put")
- */
-void 
-do_put (
-    int regname,
-    int dir,                        /* BACKWARD for 'P', FORWARD for 'p' */
-    long count,
-    int flags
-)
+    dir: BACKWARD for 'P', FORWARD for 'p' */
+void do_put(int regname, yankreg_T *reg, int dir, long count, int flags)
 {
   char_u      *ptr;
   char_u      *newp, *oldp;
@@ -2672,7 +2646,12 @@ do_put (
       y_array = &insert_string;
     }
   } else {
-    yankreg_T *reg = get_yank_register(regname, YREG_PASTE);
+    // in case of replacing visually selected text
+    // the yankreg might already have been saved to avoid
+    // just restoring the deleted text.
+    if (reg == NULL) {
+      reg = get_yank_register(regname, YREG_PASTE);
+    }
 
     y_type = reg->y_type;
     y_width = reg->y_width;

test/functional/clipboard/clipboard_provider_spec.lua

@@ -73,6 +73,12 @@ local function basic_register_test(noblock)
       stuf, stuff and some more
       me tsome textsome some text, stuff and some more]])
   end
+
+  -- pasting in visual does unnamed delete of visual selection
+  feed('ggdG')
+  insert("one and two and three")
+  feed('"ayiwbbviw"ap^viwp$viw"-p')
+  expect("two and three and one")
 end
 
 describe('the unnamed register', function()
@@ -241,6 +247,14 @@ describe('clipboard usage', function()
       eq('\02210', eval('getregtype()'))
     end)
 
+    it('yanks visual selection when pasting', function()
+      insert("indeed visual")
+      execute("let g:test_clip['*'] = [['clipboard'], 'c']")
+      feed("viwp")
+      eq({{'visual'}, 'v'}, eval("g:test_clip['*']"))
+      expect("indeed clipboard")
+    end)
+
   end)
 
   it('supports :put', function()