Fix some "out of memory" comments and few cosmetics

src/nvim/charset.c

@@ -9,6 +9,7 @@
 #include "nvim/vim.h"
 #include "nvim/charset.h"
 #include "nvim/farsi.h"
+#include "nvim/func_attr.h"
 #include "nvim/main.h"
 #include "nvim/mbyte.h"
 #include "nvim/memline.h"
@@ -321,12 +322,12 @@ void trans_characters(char_u *buf, int bufsize)
 }
 
 /// Translate a string into allocated memory, replacing special chars with
-/// printable chars.  Returns NULL when out of memory.
+/// printable chars.
 ///
 /// @param s
 ///
 /// @return translated string
-char_u *transstr(char_u *s)
+char_u *transstr(char_u *s) FUNC_ATTR_NONNULL_RET
 {
   char_u *res;
   char_u *p;

src/nvim/edit.c

@@ -7975,7 +7975,7 @@ static int ins_tab(void)
 
 /*
  * Handle CR or NL in insert mode.
- * Return TRUE when out of memory or can't undo.
+ * Return TRUE when it can't undo.
  */
 static int ins_eol(int c)
 {

src/nvim/eval.c

@@ -5150,7 +5150,7 @@ static void list_extend(list_T *l1, list_T *l2, listitem_T *bef)
 
 /*
  * Concatenate lists "l1" and "l2" into a new list, stored in "tv".
- * Return FAIL when out of memory.
+ * Return FAIL on failure to copy.
  */
 static int list_concat(list_T *l1, list_T *l2, typval_T *tv)
 {
@@ -5175,7 +5175,7 @@ static int list_concat(list_T *l1, list_T *l2, typval_T *tv)
  * Make a copy of list "orig".  Shallow if "deep" is FALSE.
  * The refcount of the new list is set to 1.
  * See item_copy() for "copyID".
- * Returns NULL when out of memory.
+ * Returns NULL if orig is NULL or some failure happens.
  */
 static list_T *list_copy(list_T *orig, int deep, int copyID)
 {
@@ -5721,7 +5721,7 @@ void dictitem_free(dictitem_T *item)
  * Make a copy of dict "d".  Shallow if "deep" is FALSE.
  * The refcount of the new dict is set to 1.
  * See item_copy() for "copyID".
- * Returns NULL when out of memory.
+ * Returns NULL if orig is NULL or some other failure.
  */
 static dict_T *dict_copy(dict_T *orig, int deep, int copyID)
 {
@@ -5865,7 +5865,7 @@ dictitem_T *dict_find(dict_T *d, char_u *key, int len)
 /*
  * Get a string item from a dictionary.
  * When "save" is TRUE allocate memory for it.
- * Returns NULL if the entry doesn't exist or out of memory.
+ * Returns NULL if the entry doesn't exist or some other failure.
  */
 char_u *get_dict_string(dict_T *d, char_u *key, int save)
 {
@@ -5883,13 +5883,11 @@ char_u *get_dict_string(dict_T *d, char_u *key, int save)
 
 /*
  * Get a number item from a dictionary.
- * Returns 0 if the entry doesn't exist or out of memory.
+ * Returns 0 if the entry doesn't exist.
  */
 long get_dict_number(dict_T *d, char_u *key)
 {
-  dictitem_T  *di;
-
-  di = dict_find(d, key, -1);
+  dictitem_T *di = dict_find(d, key, -1);
   if (di == NULL)
     return 0;
   return get_tv_number(&di->di_tv);
@@ -17436,7 +17434,7 @@ static void func_do_profile(ufunc_T *fp)
   fp->uf_tml_idx = -1;
   if (fp->uf_tml_count == NULL || fp->uf_tml_total == NULL
       || fp->uf_tml_self == NULL)
-    return;         /* out of memory */
+    return;
 
   fp->uf_profiling = TRUE;
 }

src/nvim/ex_cmds.c

@@ -1853,7 +1853,7 @@ int viminfo_readline(vir_T *virp)
  *
  * Check for a long line as written by viminfo_writestring().
  *
- * Return the string in allocated memory (NULL when out of memory).
+ * Return the string in allocated memory (or NULL to indicate failure).
  */
 char_u *
 viminfo_readstring (

src/nvim/mbyte.c

@@ -3528,8 +3528,6 @@ static char_u * iconv_string(vimconv_T *vcp, char_u *str, int slen, int *unconvl
         memmove(p, result, done);
       free(result);
       result = p;
-      if (result == NULL)       /* out of memory */
-        break;
     }
 
     to = (char *)result + done;