vim-patch:9.1.1169: using global variable for get_insert()/get_lambda_name() (#32713)

Problem:  using global variable for get_insert()/get_lambda_name()
          (after v9.1.1151)
Solution: let the functions return a string_T object instead
          (Yee Cheng Chin)

In vim/vim#16720, `get_insert()` was modified to store a string length in a
global variable to be queried immediately by another `get_insert_len()`
function, which is somewhat fragile. Instead, just have the function
itself return a `string_T` object instead. Also do the same for
`get_lambda_name()` which has similar issues.

closes: vim/vim#16775

https://github.com/vim/vim/commit/0b5fe420715786249cd121d845dbd6a81f962d1b

Co-authored-by: Yee Cheng Chin <ychin.git@gmail.com>

4 files changed, 29 insertions, 58 deletions

diff --git a/src/nvim/edit.c b/src/nvim/edit.c
index f5ba9c1c05..c3f204045a 100644
--- a/src/nvim/edit.c
+++ b/src/nvim/edit.c
@@ -9,6 +9,7 @@
 #include <uv.h>
 
 #include "klib/kvec.h"
+#include "nvim/api/private/defs.h"
 #include "nvim/ascii_defs.h"
 #include "nvim/autocmd.h"
 #include "nvim/autocmd_defs.h"
@@ -99,7 +100,6 @@ typedef struct {
   int did_restart_edit;              // remember if insert mode was restarted
                                      // after a ctrl+o
   bool nomove;
-  char *ptr;
 } InsertState;
 
 #ifdef INCLUDE_GENERATED_DECLARATIONS
@@ -163,15 +163,8 @@ static void insert_enter(InsertState *s)
   if (s->cmdchar != 'r' && s->cmdchar != 'v') {
     pos_T save_cursor = curwin->w_cursor;
 
-    if (s->cmdchar == 'R') {
-      s->ptr = "r";
-    } else if (s->cmdchar == 'V') {
-      s->ptr = "v";
-    } else {
-      s->ptr = "i";
-    }
-
-    set_vim_var_string(VV_INSERTMODE, s->ptr, 1);
+    const char *const ptr = s->cmdchar == 'R' ? "r" : s->cmdchar == 'V' ? "v" : "i";
+    set_vim_var_string(VV_INSERTMODE, ptr, 1);
     set_vim_var_string(VV_CHAR, NULL, -1);
     ins_apply_autocmds(EVENT_INSERTENTER);
 
@@ -288,14 +281,15 @@ static void insert_enter(InsertState *s)
     // column.  Eg after "^O$" or "^O80|".
     validate_virtcol(curwin);
     update_curswant();
+    const char *ptr;
     if (((ins_at_eol && curwin->w_cursor.lnum == o_lnum)
          || curwin->w_curswant > curwin->w_virtcol)
-        && *(s->ptr = get_cursor_line_ptr() + curwin->w_cursor.col) != NUL) {
-      if (s->ptr[1] == NUL) {
+        && *(ptr = get_cursor_line_ptr() + curwin->w_cursor.col) != NUL) {
+      if (ptr[1] == NUL) {
         curwin->w_cursor.col++;
       } else {
-        s->i = utfc_ptr2len(s->ptr);
-        if (s->ptr[s->i] == NUL) {
+        s->i = utfc_ptr2len(ptr);
+        if (ptr[s->i] == NUL) {
           curwin->w_cursor.col += s->i;
         }
       }
@@ -335,12 +329,10 @@ static void insert_enter(InsertState *s)
 
   // Get the current length of the redo buffer, those characters have to be
   // skipped if we want to get to the inserted characters.
-  s->ptr = get_inserted();
-  if (s->ptr == NULL) {
-    new_insert_skip = 0;
-  } else {
-    new_insert_skip = (int)get_inserted_len();
-    xfree(s->ptr);
+  String inserted = get_inserted();
+  new_insert_skip = (int)inserted.size;
+  if (inserted.data != NULL) {
+    xfree(inserted.data);
   }
 
   old_indent = 0;
@@ -2337,14 +2329,14 @@ static void stop_insert(pos_T *end_insert_pos, int esc, int nomove)
   // Save the inserted text for later redo with ^@ and CTRL-A.
   // Don't do it when "restart_edit" was set and nothing was inserted,
   // otherwise CTRL-O w and then <Left> will clear "last_insert".
-  char *ptr = get_inserted();
-  int added = ptr == NULL ? 0 : (int)get_inserted_len() - new_insert_skip;
+  String inserted = get_inserted();
+  int added = inserted.data == NULL ? 0 : (int)inserted.size - new_insert_skip;
   if (did_restart_edit == 0 || added > 0) {
     xfree(last_insert);
-    last_insert = ptr;
+    last_insert = inserted.data;
     last_insert_skip = added < 0 ? 0 : new_insert_skip;
   } else {
-    xfree(ptr);
+    xfree(inserted.data);
   }
 
   if (!arrow_used && end_insert_pos != NULL) {
diff --git a/src/nvim/eval/userfunc.c b/src/nvim/eval/userfunc.c
index f386dd28b9..c5357d507c 100644
--- a/src/nvim/eval/userfunc.c
+++ b/src/nvim/eval/userfunc.c
@@ -8,6 +8,7 @@
 #include <stdlib.h>
 #include <string.h>
 
+#include "nvim/api/private/defs.h"
 #include "nvim/ascii_defs.h"
 #include "nvim/autocmd.h"
 #include "nvim/autocmd_defs.h"
@@ -265,29 +266,16 @@ static void register_closure(ufunc_T *fp)
 }
 
 static char lambda_name[8 + NUMBUFLEN];
-static size_t lambda_namelen = 0;
 
 /// @return  a name for a lambda.  Returned in static memory.
-char *get_lambda_name(void)
+static String get_lambda_name(void)
 {
   static int lambda_no = 0;
 
   int n = snprintf(lambda_name, sizeof(lambda_name), "<lambda>%d", ++lambda_no);
-  if (n < 1) {
-    lambda_namelen = 0;
-  } else if (n >= (int)sizeof(lambda_name)) {
-    lambda_namelen = sizeof(lambda_name) - 1;
-  } else {
-    lambda_namelen = (size_t)n;
-  }
 
-  return lambda_name;
-}
-
-/// Get the length of the last lambda name.
-size_t get_lambda_name_len(void)
-{
-  return lambda_namelen;
+  return cbuf_as_string(lambda_name,
+                        n < 1 ? 0 : (size_t)MIN(n, (int)sizeof(lambda_name) - 1));
 }
 
 /// Allocate a "ufunc_T" for a function called "name".
@@ -371,10 +359,8 @@ int get_lambda_tv(char **arg, typval_T *rettv, evalarg_T *evalarg)
     int flags = 0;
     garray_T newlines;
 
-    char *name = get_lambda_name();
-    size_t namelen = get_lambda_name_len();
-
-    fp = alloc_ufunc(name, namelen);
+    String name = get_lambda_name();
+    fp = alloc_ufunc(name.data, name.size);
     pt = xcalloc(1, sizeof(partial_T));
 
     ga_init(&newlines, (int)sizeof(char *), 1);
@@ -4142,9 +4128,8 @@ bool set_ref_in_func(char *name, ufunc_T *fp_in, int copyID)
 /// Registers a luaref as a lambda.
 char *register_luafunc(LuaRef ref)
 {
-  char *name = get_lambda_name();
-  size_t namelen = get_lambda_name_len();
-  ufunc_T *fp = alloc_ufunc(name, namelen);
+  String name = get_lambda_name();
+  ufunc_T *fp = alloc_ufunc(name.data, name.size);
 
   fp->uf_refcount = 1;
   fp->uf_varargs = true;
diff --git a/src/nvim/getchar.c b/src/nvim/getchar.c
index ac817ab9e6..899293e9f6 100644
--- a/src/nvim/getchar.c
+++ b/src/nvim/getchar.c
@@ -155,9 +155,6 @@ static uint8_t noremapbuf_init[TYPELEN_INIT];  ///< initial typebuf.tb_noremap
 
 static size_t last_recorded_len = 0;  ///< number of last recorded chars
 
-static size_t last_get_inserted_len = 0;  ///< length of the string returned from the
-                                          ///< last call to get_inserted()
-
 enum {
   KEYLEN_PART_KEY = -1,  ///< keylen value for incomplete key-code
   KEYLEN_PART_MAP = -2,  ///< keylen value for incomplete mapping
@@ -254,15 +251,11 @@ char *get_recorded(void)
 
 /// Return the contents of the redo buffer as a single string.
 /// K_SPECIAL in the returned string is escaped.
-char *get_inserted(void)
-{
-  return get_buffcont(&redobuff, false, &last_get_inserted_len);
-}
-
-/// Return the length of string returned from the last call of get_inserted().
-size_t get_inserted_len(void)
+String get_inserted(void)
 {
-  return last_get_inserted_len;
+  size_t len = 0;
+  char *str = get_buffcont(&redobuff, false, &len);
+  return cbuf_as_string(str, len);
 }
 
 /// Add string after the current block of the given buffer
diff --git a/src/nvim/getchar.h b/src/nvim/getchar.h
index 766c5eb2a4..aa5110655c 100644
--- a/src/nvim/getchar.h
+++ b/src/nvim/getchar.h
@@ -3,6 +3,7 @@
 #include <stddef.h>  // IWYU pragma: keep
 #include <stdint.h>  // IWYU pragma: keep
 
+#include "nvim/api/private/defs.h"  // IWYU pragma: keep
 #include "nvim/eval/typval_defs.h"  // IWYU pragma: keep
 #include "nvim/getchar_defs.h"  // IWYU pragma: keep
 #include "nvim/types_defs.h"  // IWYU pragma: keep