Remove NULL/non-NULL tests after calls to vim_str(n)save()

34 files changed, 345 insertions, 691 deletions

diff --git a/src/nvim/buffer.c b/src/nvim/buffer.c
index 42b7826981..065c7e69c3 100644
--- a/src/nvim/buffer.c
+++ b/src/nvim/buffer.c
@@ -2237,9 +2237,8 @@ setfname (
       close_buffer(NULL, obuf, DOBUF_WIPE, FALSE);
     }
     sfname = vim_strsave(sfname);
-    if (ffname == NULL || sfname == NULL) {
+    if (ffname == NULL) {
       free(sfname);
-      free(ffname);
       return FAIL;
     }
 #ifdef USE_FNAME_CASE
@@ -4116,8 +4115,6 @@ chk_modeline (
     while (s[-1] != ':');
 
     s = linecopy = vim_strsave(s);      /* copy the line, it will change */
-    if (linecopy == NULL)
-      return FAIL;
 
     save_sourcing_lnum = sourcing_lnum;
     save_sourcing_name = sourcing_name;
diff --git a/src/nvim/charset.c b/src/nvim/charset.c
index 6618a7c22d..7c8284a891 100644
--- a/src/nvim/charset.c
+++ b/src/nvim/charset.c
@@ -1911,9 +1911,6 @@ void backslash_halve(char_u *p)
 char_u* backslash_halve_save(char_u *p)
 {
   char_u *res = vim_strsave(p);
-  if (res == NULL) {
-    return p;
-  }
   backslash_halve(res);
   return res;
 }
diff --git a/src/nvim/diff.c b/src/nvim/diff.c
index 0e5d1c20b7..06416639bd 100644
--- a/src/nvim/diff.c
+++ b/src/nvim/diff.c
@@ -519,10 +519,6 @@ static void diff_check_unchanged(tabpage_T *tp, diff_T *dp)
                                                 dp->df_lnum[i_org] + off_org,
                                                 FALSE));
 
-      if (line_org == NULL) {
-        return;
-      }
-
       int i_new;
       for (i_new = i_org + 1; i_new < DB_COUNT; ++i_new) {
         if (tp->tp_diffbuf[i_new] == NULL) {
@@ -972,10 +968,7 @@ void ex_diffpatch(exarg_T *eap)
     if (curbuf->b_fname != NULL) {
       newname = vim_strnsave(curbuf->b_fname,
                              (int)(STRLEN(curbuf->b_fname) + 4));
-
-      if (newname != NULL) {
-        STRCAT(newname, ".new");
-      }
+      STRCAT(newname, ".new");
     }
 
     // don't use a new tab page, each tab page has its own diffs
@@ -1580,9 +1573,6 @@ static int diff_equal_entry(diff_T *dp, int idx1, int idx2)
     char_u *line = vim_strsave(ml_get_buf(curtab->tp_diffbuf[idx1],
                                           dp->df_lnum[idx1] + i, FALSE));
 
-    if (line == NULL) {
-      return FALSE;
-    }
     int cmp = diff_cmp(line, ml_get_buf(curtab->tp_diffbuf[idx2],
                                         dp->df_lnum[idx2] + i, FALSE));
     free(line);
@@ -1886,9 +1876,6 @@ int diff_find_change(win_T *wp, linenr_T lnum, int *startp, int *endp)
 
   // Make a copy of the line, the next ml_get() will invalidate it.
   char_u *line_org = vim_strsave(ml_get_buf(wp->w_buffer, lnum, FALSE));
-  if (line_org == NULL) {
-    return FALSE;
-  }
 
   int idx = diff_buf_idx(wp->w_buffer);
   if (idx == DB_COUNT) {
@@ -2283,16 +2270,14 @@ void ex_diffgetput(exarg_T *eap)
           break;
         }
         p = vim_strsave(ml_get_buf(curtab->tp_diffbuf[idx_from], nr, FALSE));
-        if (p != NULL) {
-          ml_append(lnum + i - 1, p, 0, FALSE);
-          free(p);
-          added++;
-          if (buf_empty && (curbuf->b_ml.ml_line_count == 2)) {
-            // Added the first line into an empty buffer, need to
-            // delete the dummy empty line.
-            buf_empty = FALSE;
-            ml_delete((linenr_T)2, FALSE);
-          }
+        ml_append(lnum + i - 1, p, 0, FALSE);
+        free(p);
+        added++;
+        if (buf_empty && (curbuf->b_ml.ml_line_count == 2)) {
+          // Added the first line into an empty buffer, need to
+          // delete the dummy empty line.
+          buf_empty = FALSE;
+          ml_delete((linenr_T)2, FALSE);
         }
       }
       new_count = dp->df_count[idx_to] + added;
diff --git a/src/nvim/digraph.c b/src/nvim/digraph.c
index b7f0c40788..7f1e89e741 100644
--- a/src/nvim/digraph.c
+++ b/src/nvim/digraph.c
@@ -1818,12 +1818,10 @@ void ex_loadkeymap(exarg_T *eap)
       s = skiptowhite(p);
       kp->to = vim_strnsave(p, (int)(s - p));
 
-      if ((kp->from == NULL)
-          || (kp->to == NULL)
-          || (STRLEN(kp->from) + STRLEN(kp->to) >= KMAP_LLEN)
+      if ((STRLEN(kp->from) + STRLEN(kp->to) >= KMAP_LLEN)
           || (*kp->from == NUL)
           || (*kp->to == NUL)) {
-        if ((kp->to != NULL) && (*kp->to == NUL)) {
+        if (*kp->to == NUL) {
           EMSG(_("E791: Empty keymap entry"));
         }
         free(kp->from);
diff --git a/src/nvim/edit.c b/src/nvim/edit.c
index 440787643e..a47a39a3ac 100644
--- a/src/nvim/edit.c
+++ b/src/nvim/edit.c
@@ -1727,8 +1727,6 @@ change_indent (
 
     /* Save new line */
     new_line = vim_strsave(ml_get_curline());
-    if (new_line == NULL)
-      return;
 
     /* We only put back the new line up to the cursor */
     new_line[curwin->w_cursor.col] = NUL;
@@ -2128,10 +2126,7 @@ ins_compl_add (
   match->cp_number = -1;
   if (flags & ORIGINAL_TEXT)
     match->cp_number = 0;
-  if ((match->cp_str = vim_strnsave(str, len)) == NULL) {
-    free(match);
-    return FAIL;
-  }
+  match->cp_str = vim_strnsave(str, len);
   match->cp_icase = icase;
 
   /* match-fname is:
@@ -2210,18 +2205,16 @@ static void ins_compl_longest_match(compl_T *match)
   if (compl_leader == NULL) {
     /* First match, use it as a whole. */
     compl_leader = vim_strsave(match->cp_str);
-    if (compl_leader != NULL) {
-      had_match = (curwin->w_cursor.col > compl_col);
-      ins_compl_delete();
-      ins_bytes(compl_leader + ins_compl_len());
-      ins_redraw(FALSE);
+    had_match = (curwin->w_cursor.col > compl_col);
+    ins_compl_delete();
+    ins_bytes(compl_leader + ins_compl_len());
+    ins_redraw(FALSE);
 
-      /* When the match isn't there (to avoid matching itself) remove it
-       * again after redrawing. */
-      if (!had_match)
-        ins_compl_delete();
-      compl_used_match = FALSE;
-    }
+    /* When the match isn't there (to avoid matching itself) remove it
+     * again after redrawing. */
+    if (!had_match)
+      ins_compl_delete();
+    compl_used_match = FALSE;
   } else {
     /* Reduce the text if this match differs from compl_leader. */
     p = compl_leader;
@@ -2328,9 +2321,10 @@ void set_completion(colnr_T startcol, list_T *list)
   compl_length = (int)curwin->w_cursor.col - (int)startcol;
   /* compl_pattern doesn't need to be set */
   compl_orig_text = vim_strnsave(ml_get_curline() + compl_col, compl_length);
-  if (compl_orig_text == NULL || ins_compl_add(compl_orig_text,
-          -1, p_ic, NULL, NULL, 0, ORIGINAL_TEXT, FALSE) != OK)
+  if (ins_compl_add(compl_orig_text, -1, p_ic, NULL, NULL, 0,
+                    ORIGINAL_TEXT, FALSE) != OK) {
     return;
+  }
 
   /* Handle like dictionary completion. */
   ctrl_x_mode = CTRL_X_WHOLE_LINE;
@@ -2873,14 +2867,12 @@ static int ins_compl_bs(void)
 
   free(compl_leader);
   compl_leader = vim_strnsave(line + compl_col, (int)(p - line) - compl_col);
-  if (compl_leader != NULL) {
-    ins_compl_new_leader();
-    if (compl_shown_match != NULL)
-      /* Make sure current match is not a hidden item. */
-      compl_curr_match = compl_shown_match;
-    return NUL;
-  }
-  return K_BS;
+  ins_compl_new_leader();
+  if (compl_shown_match != NULL)
+    /* Make sure current match is not a hidden item. */
+    compl_curr_match = compl_shown_match;
+
+  return NUL;
 }
 
 /*
@@ -2980,8 +2972,7 @@ static void ins_compl_addleader(int c)
     free(compl_leader);
     compl_leader = vim_strnsave(ml_get_curline() + compl_col,
         (int)(curwin->w_cursor.col - compl_col));
-    if (compl_leader != NULL)
-      ins_compl_new_leader();
+    ins_compl_new_leader();
   }
 }
 
@@ -3003,15 +2994,10 @@ static void ins_compl_restart(void)
  */
 static void ins_compl_set_original_text(char_u *str)
 {
-  char_u      *p;
-
   /* Replace the original text entry. */
   if (compl_first_match->cp_flags & ORIGINAL_TEXT) {    /* safety check */
-    p = vim_strsave(str);
-    if (p != NULL) {
-      free(compl_first_match->cp_str);
-      compl_first_match->cp_str = p;
-    }
+    free(compl_first_match->cp_str);
+    compl_first_match->cp_str = vim_strsave(str);
   }
 }
 
@@ -4356,8 +4342,6 @@ static int ins_complete(int c)
                  ) {
         /* Match any word of at least two chars */
         compl_pattern = vim_strsave((char_u *)"\\<\\k\\k");
-        if (compl_pattern == NULL)
-          return FAIL;
         compl_col += curs_col;
         compl_length = 0;
       } else {
@@ -4432,8 +4416,6 @@ static int ins_complete(int c)
         return FAIL;
     } else if (ctrl_x_mode == CTRL_X_CMDLINE) {
       compl_pattern = vim_strnsave(line, curs_col);
-      if (compl_pattern == NULL)
-        return FAIL;
       set_cmd_context(&compl_xp, compl_pattern,
           (int)STRLEN(compl_pattern), curs_col);
       if (compl_xp.xp_context == EXPAND_UNSUCCESSFUL
@@ -4513,8 +4495,6 @@ static int ins_complete(int c)
       line = ml_get(curwin->w_cursor.lnum);
       compl_length = curs_col - compl_col;
       compl_pattern = vim_strnsave(line + compl_col, compl_length);
-      if (compl_pattern == NULL)
-        return FAIL;
     } else if (ctrl_x_mode == CTRL_X_SPELL) {
       if (spell_bad_len > 0)
         compl_col = curs_col - spell_bad_len;
@@ -4530,8 +4510,6 @@ static int ins_complete(int c)
       /* Need to obtain "line" again, it may have become invalid. */
       line = ml_get(curwin->w_cursor.lnum);
       compl_pattern = vim_strnsave(line + compl_col, compl_length);
-      if (compl_pattern == NULL)
-        return FAIL;
     } else {
       EMSG2(_(e_intern2), "ins_complete()");
       return FAIL;
@@ -4568,8 +4546,8 @@ static int ins_complete(int c)
     /* Always add completion for the original text. */
     free(compl_orig_text);
     compl_orig_text = vim_strnsave(line + compl_col, compl_length);
-    if (compl_orig_text == NULL || ins_compl_add(compl_orig_text,
-            -1, p_ic, NULL, NULL, 0, ORIGINAL_TEXT, FALSE) != OK) {
+    if (ins_compl_add(compl_orig_text, -1, p_ic, NULL, NULL, 0,
+                      ORIGINAL_TEXT, FALSE) != OK) {
       free(compl_pattern);
       compl_pattern = NULL;
       free(compl_orig_text);
@@ -6227,11 +6205,10 @@ char_u *get_last_insert_save(void)
   if (last_insert == NULL)
     return NULL;
   s = vim_strsave(last_insert + last_insert_skip);
-  if (s != NULL) {
-    len = (int)STRLEN(s);
-    if (len > 0 && s[len - 1] == ESC)           /* remove trailing ESC */
-      s[len - 1] = NUL;
-  }
+  len = (int)STRLEN(s);
+  if (len > 0 && s[len - 1] == ESC)           /* remove trailing ESC */
+    s[len - 1] = NUL;
+
   return s;
 }
 
@@ -8006,8 +7983,6 @@ static int ins_tab(void)
       pos = curwin->w_cursor;
       cursor = &pos;
       saved_line = vim_strsave(ml_get_curline());
-      if (saved_line == NULL)
-        return FALSE;
       ptr = saved_line + pos.col;
     } else {
       ptr = ml_get_cursor();
@@ -8411,7 +8386,6 @@ static colnr_T get_nolist_virtcol(void)
  */
 static char_u *do_insert_char_pre(int c)
 {
-  char_u      *res;
   char_u buf[MB_MAXBYTES + 1];
 
   /* Return quickly when there is nothing to do. */
@@ -8429,7 +8403,7 @@ static char_u *do_insert_char_pre(int c)
   ++textlock;
   set_vim_var_string(VV_CHAR, buf, -1);    /* set v:char */
 
-  res = NULL;
+  char_u *res = NULL;
   if (apply_autocmds(EVENT_INSERTCHARPRE, NULL, NULL, FALSE, curbuf)) {
     /* Get the value of v:char.  It may be empty or more than one
      * character.  Only use it when changed, otherwise continue with the
diff --git a/src/nvim/eval.c b/src/nvim/eval.c
index 86b8aaecba..44c5b2eaf5 100644
--- a/src/nvim/eval.c
+++ b/src/nvim/eval.c
@@ -1041,8 +1041,6 @@ var_redir_start (
 
   /* Make a copy of the name, it is used in redir_lval until redir ends. */
   redir_varname = vim_strsave(name);
-  if (redir_varname == NULL)
-    return FAIL;
 
   redir_lval = xcalloc(1, sizeof(lval_T));
 
@@ -2542,8 +2540,6 @@ get_lval (
           lp->ll_newkey = vim_strnsave(key, len);
         if (len == -1)
           clear_tv(&var1);
-        if (lp->ll_newkey == NULL)
-          p = NULL;
         break;
       }
       /* existing variable, need to check if it can be changed */
@@ -6353,8 +6349,6 @@ dictitem_T *dict_find(dict_T *d, char_u *key, int len)
     akey = key;
   else if (len >= AKEYLEN) {
     tofree = akey = vim_strnsave(key, len);
-    if (akey == NULL)
-      return NULL;
   } else {
     /* Avoid a malloc/free by using buf[]. */
     vim_strncpy(buf, key, len);
@@ -7264,8 +7258,6 @@ call_func (
   /* Make a copy of the name, if it comes from a funcref variable it could
    * be changed or deleted in the called function. */
   name = vim_strnsave(funcname, len);
-  if (name == NULL)
-    return ret;
 
   /*
    * In a script change <SID>name() and s:name() to K_SNR 123_name().
@@ -9677,11 +9669,9 @@ static void f_getfperm(typval_T *argvars, typval_T *rettv)
   int32_t file_perm = os_getperm(filename);
   if (file_perm >= 0) {
     perm = vim_strsave((char_u *)"---------");
-    if (perm != NULL) {
-      for (int i = 0; i < 9; i++) {
-        if (file_perm & (1 << (8 - i)))
-          perm[i] = flags[i % 3];
-      }
+    for (int i = 0; i < 9; i++) {
+      if (file_perm & (1 << (8 - i)))
+        perm[i] = flags[i % 3];
     }
   }
   rettv->v_type = VAR_STRING;
@@ -11761,8 +11751,6 @@ static int mkdir_recurse(char_u *dir, int prot)
 
   /* If the directory exists we're done.  Otherwise: create it.*/
   updir = vim_strnsave(dir, (int)(p - dir));
-  if (updir == NULL)
-    return FAIL;
   if (os_isdir(updir))
     r = OK;
   else if (mkdir_recurse(updir, prot) == OK)
@@ -12107,17 +12095,11 @@ static void f_readfile(typval_T *argvars, typval_T *rettv)
           /* Change "prev" buffer to be the right size.  This way
            * the bytes are only copied once, and very long lines are
            * allocated only once.  */
-          if ((s = xrealloc(prev, prevlen + len + 1)) != NULL) {
-            memmove(s + prevlen, start, len);
-            s[prevlen + len] = NUL;
-            prev = NULL;             /* the list will own the string */
-            prevlen = prevsize = 0;
-          }
-        }
-        if (s == NULL) {
-          do_outofmem_msg((long_u) prevlen + len + 1);
-          failed = TRUE;
-          break;
+          s = xrealloc(prev, prevlen + len + 1);
+          memcpy(s + prevlen, start, len);
+          s[prevlen + len] = NUL;
+          prev = NULL;             /* the list will own the string */
+          prevlen = prevsize = 0;
         }
 
         if ((li = listitem_alloc()) == NULL) {
@@ -12592,11 +12574,10 @@ static void f_resolve(typval_T *argvars, typval_T *rettv)
       q = path_next_component(remain + 1);
       len = q - remain - (*q != NUL);
       cpy = vim_strnsave(p, STRLEN(p) + len);
-      if (cpy != NULL) {
-        STRNCAT(cpy, remain, len);
-        free(p);
-        p = cpy;
-      }
+      STRNCAT(cpy, remain, len);
+      free(p);
+      p = cpy;
+
       /* Shorten "remain". */
       if (*q != NUL)
         STRMOVE(remain, q - 1);
@@ -14940,33 +14921,30 @@ static void f_tanh(typval_T *argvars, typval_T *rettv)
  */
 static void f_tolower(typval_T *argvars, typval_T *rettv)
 {
-  char_u      *p;
-
-  p = vim_strsave(get_tv_string(&argvars[0]));
+  char_u *p = vim_strsave(get_tv_string(&argvars[0]));
   rettv->v_type = VAR_STRING;
   rettv->vval.v_string = p;
 
-  if (p != NULL)
-    while (*p != NUL) {
-      int l;
-
-      if (enc_utf8) {
-        int c, lc;
-
-        c = utf_ptr2char(p);
-        lc = utf_tolower(c);
-        l = utf_ptr2len(p);
-        /* TODO: reallocate string when byte count changes. */
-        if (utf_char2len(lc) == l)
-          utf_char2bytes(lc, p);
-        p += l;
-      } else if (has_mbyte && (l = (*mb_ptr2len)(p)) > 1)
-        p += l;                 /* skip multi-byte character */
-      else {
-        *p = TOLOWER_LOC(*p);         /* note that tolower() can be a macro */
-        ++p;
-      }
+  while (*p != NUL) {
+    int l;
+
+    if (enc_utf8) {
+      int c, lc;
+
+      c = utf_ptr2char(p);
+      lc = utf_tolower(c);
+      l = utf_ptr2len(p);
+      /* TODO: reallocate string when byte count changes. */
+      if (utf_char2len(lc) == l)
+        utf_char2bytes(lc, p);
+      p += l;
+    } else if (has_mbyte && (l = (*mb_ptr2len)(p)) > 1)
+      p += l;                 /* skip multi-byte character */
+    else {
+      *p = TOLOWER_LOC(*p);         /* note that tolower() can be a macro */
+      ++p;
     }
+  }
 }
 
 /*
@@ -17428,8 +17406,6 @@ void ex_function(exarg_T *eap)
       c = *p;
       *p = NUL;
       arg = vim_strsave(arg);
-      if (arg == NULL)
-        goto erret;
 
       /* Check for duplicate argument name. */
       for (i = 0; i < newargs.ga_len; ++i)
@@ -17621,11 +17597,9 @@ void ex_function(exarg_T *eap)
      * allocates 250 bytes per line, this saves 80% on average.  The cost
      * is an extra alloc/free. */
     p = vim_strsave(theline);
-    if (p != NULL) {
-      if (line_arg == NULL)
-        free(theline);
-      theline = p;
-    }
+    if (line_arg == NULL)
+      free(theline);
+    theline = p;
 
     ((char_u **)(newlines.ga_data))[newlines.ga_len++] = theline;
 
@@ -17694,8 +17668,6 @@ void ex_function(exarg_T *eap)
     free(name);
     sprintf(numbuf, "%d", ++func_nr);
     name = vim_strsave((char_u *)numbuf);
-    if (name == NULL)
-      goto erret;
   }
 
   if (fp == NULL) {
@@ -19538,11 +19510,9 @@ repeat:
         /* Only replace it when it starts with '~' */
         if (*dirname == '~') {
           s = vim_strsave(dirname);
-          if (s != NULL) {
-            *fnamep = s;
-            free(*bufp);
-            *bufp = s;
-          }
+          *fnamep = s;
+          free(*bufp);
+          *bufp = s;
         }
       }
       free(pbuf);
@@ -19563,11 +19533,8 @@ repeat:
     *fnamelen = (int)(tail - *fnamep);
     if (*fnamelen == 0) {
       /* Result is empty.  Turn it into "." to make ":cd %:h" work. */
-      p = vim_strsave((char_u *)".");
-      if (p == NULL)
-        return -1;
       free(*bufp);
-      *bufp = *fnamep = tail = p;
+      *bufp = *fnamep = tail = vim_strsave((char_u *)".");
       *fnamelen = 1;
     } else {
       while (tail > s && !after_pathsep(s, tail))
@@ -19645,23 +19612,19 @@ repeat:
           s = p + 1;
           /* find end of substitution */
           p = vim_strchr(s, sep);
-          if (p != NULL) {
-            sub = vim_strnsave(s, (int)(p - s));
-            str = vim_strnsave(*fnamep, *fnamelen);
-            if (sub != NULL && str != NULL) {
-              *usedlen = (int)(p + 1 - src);
-              s = do_string_sub(str, pat, sub, flags);
-              if (s != NULL) {
-                *fnamep = s;
-                *fnamelen = (int)STRLEN(s);
-                free(*bufp);
-                *bufp = s;
-                didit = TRUE;
-              }
-            }
-            free(sub);
-            free(str);
+          sub = vim_strnsave(s, (int)(p - s));
+          str = vim_strnsave(*fnamep, *fnamelen);
+          *usedlen = (int)(p + 1 - src);
+          s = do_string_sub(str, pat, sub, flags);
+          if (s != NULL) {
+            *fnamep = s;
+            *fnamelen = (int)STRLEN(s);
+            free(*bufp);
+            *bufp = s;
+            didit = TRUE;
           }
+          free(sub);
+          free(str);
           free(pat);
         }
       }
diff --git a/src/nvim/ex_cmds.c b/src/nvim/ex_cmds.c
index 0918e73b8a..c2bf9e96e5 100644
--- a/src/nvim/ex_cmds.c
+++ b/src/nvim/ex_cmds.c
@@ -695,12 +695,10 @@ int do_move(linenr_T line1, linenr_T line2, linenr_T dest)
     return FAIL;
   for (extra = 0, l = line1; l <= line2; l++) {
     str = vim_strsave(ml_get(l + extra));
-    if (str != NULL) {
-      ml_append(dest + l - line1, str, (colnr_T)0, FALSE);
-      free(str);
-      if (dest < line1)
-        extra++;
-    }
+    ml_append(dest + l - line1, str, (colnr_T)0, FALSE);
+    free(str);
+    if (dest < line1)
+      extra++;
   }
 
   /*
@@ -803,10 +801,9 @@ void ex_copy(linenr_T line1, linenr_T line2, linenr_T n)
     /* need to use vim_strsave() because the line will be unlocked within
      * ml_append() */
     p = vim_strsave(ml_get(line1));
-    if (p != NULL) {
-      ml_append(curwin->w_cursor.lnum, p, (colnr_T)0, FALSE);
-      free(p);
-    }
+    ml_append(curwin->w_cursor.lnum, p, (colnr_T)0, FALSE);
+    free(p);
+
     /* situation 2: skip already copied lines */
     if (line1 == n)
       line1 = curwin->w_cursor.lnum;
@@ -1886,8 +1883,6 @@ viminfo_readstring (
     s = retval + 1;         /* Skip the leading '<' */
   } else {
     retval = vim_strsave(virp->vir_line + off);
-    if (retval == NULL)
-      return NULL;
     s = retval;
   }
 
@@ -3937,17 +3932,14 @@ void do_sub(exarg_T *eap)
                  * what matches.  Temporarily replace the line
                  * and change it back afterwards. */
                 orig_line = vim_strsave(ml_get(lnum));
-                if (orig_line != NULL) {
-                  char_u *new_line = concat_str(new_start,
-                                                sub_firstline + copycol);
-
-                  // Position the cursor relative to the end of the line, the
-                  // previous substitute may have inserted or deleted characters
-                  // before the cursor.
-                  len_change = (int)STRLEN(new_line) - (int)STRLEN(orig_line);
-                  curwin->w_cursor.col += len_change;
-                  ml_replace(lnum, new_line, FALSE);
-                }
+                char_u *new_line = concat_str(new_start, sub_firstline + copycol);
+
+                // Position the cursor relative to the end of the line, the
+                // previous substitute may have inserted or deleted characters
+                // before the cursor.
+                len_change = (int)STRLEN(new_line) - (int)STRLEN(orig_line);
+                curwin->w_cursor.col += len_change;
+                ml_replace(lnum, new_line, FALSE);
               }
 
               search_match_lines = regmatch.endpos[0].lnum
@@ -5769,11 +5761,6 @@ void ex_sign(exarg_T *eap)
 			next_sign_typenr = 1; /* wrap around */
 
 		    sp->sn_name = vim_strsave(arg);
-		    if (sp->sn_name == NULL)  /* out of memory */
-		    {
-			free(sp);
-			return;
-		    }
 
 		    /* add the new sign to the list of signs */
 		    if (sp_prev == NULL)
@@ -5837,7 +5824,7 @@ void ex_sign(exarg_T *eap)
 			len = (int)(p - arg + ((cells == 1) ? 1 : 0));
 			sp->sn_text = vim_strnsave(arg, len);
 
-			if (sp->sn_text != NULL && cells == 1)
+			if (cells == 1)
 			    STRCPY(sp->sn_text + len - 1, " ");
 		    }
 		    else if (STRNCMP(arg, "linehl=", 7) == 0)
diff --git a/src/nvim/ex_cmds2.c b/src/nvim/ex_cmds2.c
index 3f20c59b2b..b4155b417d 100644
--- a/src/nvim/ex_cmds2.c
+++ b/src/nvim/ex_cmds2.c
@@ -1920,8 +1920,6 @@ void ex_argedit(exarg_T *eap)
   if (i == ARGCOUNT) {
     /* Can't find it, add it to the argument list. */
     s = vim_strsave(eap->arg);
-    if (s == NULL)
-      return;
     i = alist_add_list(1, &s,
         eap->addr_count > 0 ? (int)eap->line2 : curwin->w_arg_idx + 1);
     curwin->w_arg_idx = i;
@@ -2252,8 +2250,8 @@ void        *cookie;
   /* Make a copy of 'runtimepath'.  Invoking the callback may change the
    * value. */
   rtp_copy = vim_strsave(p_rtp);
-  buf = xmalloc(MAXPATHL);
-  if (rtp_copy != NULL) {
+  buf = xmallocz(MAXPATHL);
+  {
     if (p_verbose > 1 && name != NULL) {
       verbose_enter();
       smsg((char_u *)_("Searching for \"%s\" in \"%s\""),
@@ -2594,10 +2592,8 @@ do_source (
     p = string_convert(&cookie.conv, firstline + 3, NULL);
     if (p == NULL)
       p = vim_strsave(firstline + 3);
-    if (p != NULL) {
-      free(firstline);
-      firstline = p;
-    }
+    free(firstline);
+    firstline = p;
   }
 
 #ifdef STARTUPTIME
@@ -3483,8 +3479,6 @@ static char_u **find_locales(void)
   while (loc != NULL) {
     ga_grow(&locales_ga, 1);
     loc = vim_strsave(loc);
-    if (loc == NULL)
-      break;
 
     ((char_u **)locales_ga.ga_data)[locales_ga.ga_len++] = loc;
     loc = (char_u *)strtok(NULL, "\n");
diff --git a/src/nvim/ex_docmd.c b/src/nvim/ex_docmd.c
index 368d5c9b0c..491f7d671e 100644
--- a/src/nvim/ex_docmd.c
+++ b/src/nvim/ex_docmd.c
@@ -721,11 +721,6 @@ int flags;
     /* 3. Make a copy of the command so we can mess with it. */
     else if (cmdline_copy == NULL) {
       next_cmdline = vim_strsave(next_cmdline);
-      if (next_cmdline == NULL) {
-        EMSG(_(e_outofmem));
-        retval = FAIL;
-        break;
-      }
     }
     cmdline_copy = next_cmdline;
 
@@ -4299,10 +4294,6 @@ static int uc_add_command(char_u *name, size_t name_len, char_u *rep, long argt,
   if (rep_buf == NULL) {
     /* Can't replace termcodes - try using the string as is */
     rep_buf = vim_strsave(rep);
-
-    /* Give up if out of memory */
-    if (rep_buf == NULL)
-      return FAIL;
   }
 
   /* get address of growarray: global or in curbuf */
@@ -4349,8 +4340,7 @@ static int uc_add_command(char_u *name, size_t name_len, char_u *rep, long argt,
   if (cmp != 0) {
     ga_grow(gap, 1);
 
-    if ((p = vim_strnsave(name, (int)name_len)) == NULL)
-      goto fail;
+    p = vim_strnsave(name, (int)name_len);
 
     cmd = USER_CMD_GA(gap, i);
     memmove(cmd + 1, cmd, (gap->ga_len - i) * sizeof(ucmd_T));
@@ -5256,12 +5246,11 @@ static void ex_colorscheme(exarg_T *eap)
     char_u *expr = vim_strsave((char_u *)"g:colors_name");
     char_u *p = NULL;
 
-    if (expr != NULL) {
-      ++emsg_off;
-      p = eval_to_string(expr, NULL, FALSE);
-      --emsg_off;
-      free(expr);
-    }
+    ++emsg_off;
+    p = eval_to_string(expr, NULL, FALSE);
+    --emsg_off;
+    free(expr);
+
     if (p != NULL) {
       MSG(p);
       free(p);
@@ -7994,8 +7983,6 @@ char_u *expand_sfile(char_u *arg)
   char_u      *p;
 
   result = vim_strsave(arg);
-  if (result == NULL)
-    return NULL;
 
   for (p = result; *p; ) {
     if (STRNCMP(p, "<sfile>", 7) != 0)
diff --git a/src/nvim/ex_eval.c b/src/nvim/ex_eval.c
index cc2d4b6405..277f7d8cfb 100644
--- a/src/nvim/ex_eval.c
+++ b/src/nvim/ex_eval.c
@@ -250,11 +250,7 @@ int cause_errthrow(char_u *mesg, int severe, int *ignore)
         EMSG(_(e_outofmem));
       } else {
         elem->msg = vim_strsave(mesg);
-        if (elem->msg == NULL) {
-          free(elem);
-          suppress_errthrow = TRUE;
-          EMSG(_(e_outofmem));
-        } else {
+        {
           elem->next = NULL;
           elem->throw_msg = NULL;
           *plist = elem;
@@ -402,15 +398,11 @@ char_u *get_exception_string(void *value, int type, char_u *cmdname, int *should
       cmdlen = (int)STRLEN(cmdname);
       ret = vim_strnsave((char_u *)"Vim(",
           4 + cmdlen + 2 + (int)STRLEN(mesg));
-      if (ret == NULL)
-        return ret;
       STRCPY(&ret[4], cmdname);
       STRCPY(&ret[4 + cmdlen], "):");
       val = ret + 4 + cmdlen + 2;
     } else {
       ret = vim_strnsave((char_u *)"Vim:", 4 + (int)STRLEN(mesg));
-      if (ret == NULL)
-        return ret;
       val = ret + 4;
     }
 
@@ -493,11 +485,6 @@ static int throw_exception(void *value, int type, char_u *cmdname)
   excp->type = type;
   excp->throw_name = vim_strsave(sourcing_name == NULL
       ? (char_u *)"" : sourcing_name);
-  if (excp->throw_name == NULL) {
-    if (should_free)
-      free(excp->value);
-    goto nomem;
-  }
   excp->throw_lnum = sourcing_lnum;
 
   if (p_verbose >= 13 || debug_break_level > 0) {
diff --git a/src/nvim/ex_getln.c b/src/nvim/ex_getln.c
index 99915525ae..63952f8781 100644
--- a/src/nvim/ex_getln.c
+++ b/src/nvim/ex_getln.c
@@ -1196,8 +1196,7 @@ getcmdline (
 
       /* save current command string so it can be restored later */
       if (lookfor == NULL) {
-        if ((lookfor = vim_strsave(ccline.cmdbuff)) == NULL)
-          goto cmdline_not_changed;
+        lookfor = vim_strsave(ccline.cmdbuff);
         lookfor[ccline.cmdpos] = NUL;
       }
 
@@ -4510,8 +4509,7 @@ add_to_history (
     /* Store the separator after the NUL of the string. */
     len = (int)STRLEN(new_entry);
     hisptr->hisstr = vim_strnsave(new_entry, len + 2);
-    if (hisptr->hisstr != NULL)
-      hisptr->hisstr[len + 1] = sep;
+    hisptr->hisstr[len + 1] = sep;
 
     hisptr->hisnum = ++hisnum[histype];
     hisptr->viminfo = FALSE;
diff --git a/src/nvim/file_search.c b/src/nvim/file_search.c
index dbef8b422d..5faa112150 100644
--- a/src/nvim/file_search.c
+++ b/src/nvim/file_search.c
@@ -322,8 +322,6 @@ vim_findfile_init (
       search_ctx->ffsc_start_dir = FullName_save(ff_expand_buffer, FALSE);
     } else
       search_ctx->ffsc_start_dir = vim_strnsave(rel_fname, len);
-    if (search_ctx->ffsc_start_dir == NULL)
-      goto error_return;
     if (*++path != NUL)
       ++path;
   } else if (*path == NUL || !vim_isAbsName(path)) {
@@ -344,8 +342,6 @@ vim_findfile_init (
       goto error_return;
 
     search_ctx->ffsc_start_dir = vim_strsave(ff_expand_buffer);
-    if (search_ctx->ffsc_start_dir == NULL)
-      goto error_return;
 
 #ifdef BACKSLASH_IN_FILENAME
     /* A path that starts with "/dir" is relative to the drive, not to the
@@ -458,9 +454,6 @@ vim_findfile_init (
     }
     ff_expand_buffer[len] = NUL;
     search_ctx->ffsc_wc_path = vim_strsave(ff_expand_buffer);
-
-    if (search_ctx->ffsc_wc_path == NULL)
-      goto error_return;
   } else
     search_ctx->ffsc_fix_path = vim_strsave(path);
 
@@ -469,8 +462,6 @@ vim_findfile_init (
      * This is needed if the parameter path is fully qualified.
      */
     search_ctx->ffsc_start_dir = vim_strsave(search_ctx->ffsc_fix_path);
-    if (search_ctx->ffsc_start_dir == NULL)
-      goto error_return;
     search_ctx->ffsc_fix_path[0] = NUL;
   }
 
@@ -536,11 +527,7 @@ vim_findfile_init (
     goto error_return;
 
   ff_push(search_ctx, sptr);
-
   search_ctx->ffsc_file_to_search = vim_strsave(filename);
-  if (search_ctx->ffsc_file_to_search == NULL)
-    goto error_return;
-
   return search_ctx;
 
 error_return:
@@ -1070,10 +1057,6 @@ static ff_visited_list_hdr_T *ff_get_visited_list(char_u *filename, ff_visited_l
 
   retptr->ffvl_visited_list = NULL;
   retptr->ffvl_filename = vim_strsave(filename);
-  if (retptr->ffvl_filename == NULL) {
-    free(retptr);
-    return NULL;
-  }
   retptr->ffvl_next = *list_headp;
   *list_headp = retptr;
 
@@ -1185,9 +1168,7 @@ static int ff_check_visited(ff_visited_T **visited_list, char_u *fname, char_u *
  */
 static ff_stack_T *ff_create_stack_element(char_u *fix_part, char_u *wc_part, int level, int star_star_empty)
 {
-  ff_stack_T  *new;
-
-  new = (ff_stack_T *)alloc((unsigned)sizeof(ff_stack_T));
+  ff_stack_T *new = xmalloc(sizeof(ff_stack_T));
 
   new->ffs_prev          = NULL;
   new->ffs_filearray     = NULL;
@@ -1206,13 +1187,6 @@ static ff_stack_T *ff_create_stack_element(char_u *fix_part, char_u *wc_part, in
     wc_part  = (char_u *)"";
   new->ffs_wc_path = vim_strsave(wc_part);
 
-  if (new->ffs_fix_path == NULL
-      || new->ffs_wc_path == NULL
-      ) {
-    ff_free_stack_element(new);
-    new = NULL;
-  }
-
   return new;
 }
 
@@ -1429,10 +1403,6 @@ find_file_in_path_option (
 
     free(ff_file_to_find);
     ff_file_to_find = vim_strsave(NameBuff);
-    if (ff_file_to_find == NULL) {      /* out of memory */
-      file_name = NULL;
-      goto theend;
-    }
   }
 
   rel_to_curdir = (ff_file_to_find[0] == '.'
diff --git a/src/nvim/fileio.c b/src/nvim/fileio.c
index 4112c5288d..4b5e524bc1 100644
--- a/src/nvim/fileio.c
+++ b/src/nvim/fileio.c
@@ -2138,11 +2138,9 @@ static char_u *next_fenc(char_u **pp)
   } else {
     r = vim_strnsave(*pp, (int)(p - *pp));
     *pp = p + 1;
-    if (r != NULL) {
-      p = enc_canonize(r);
-      free(r);
-      r = p;
-    }
+    p = enc_canonize(r);
+    free(r);
+    r = p;
   }
   if (r == NULL) {      /* out of memory */
     r = (char_u *)"";
@@ -5037,7 +5035,7 @@ static int move_lines(buf_T *frombuf, buf_T *tobuf)
   curbuf = tobuf;
   for (lnum = 1; lnum <= frombuf->b_ml.ml_line_count; ++lnum) {
     p = vim_strsave(ml_get_buf(frombuf, lnum, FALSE));
-    if (p == NULL || ml_append(lnum - 1, p, 0, FALSE) == FAIL) {
+    if (ml_append(lnum - 1, p, 0, FALSE) == FAIL) {
       free(p);
       retval = FAIL;
       break;
@@ -6037,8 +6035,6 @@ static int au_new_group(char_u *name)
     }
 
     AUGROUP_NAME(i) = vim_strsave(name);
-    if (AUGROUP_NAME(i) == NULL)
-      return AUGROUP_ERROR;
     if (i == augroups.ga_len)
       ++augroups.ga_len;
   }
@@ -6242,18 +6238,14 @@ char_u *au_event_disable(char *what)
   char_u      *save_ei;
 
   save_ei = vim_strsave(p_ei);
-  if (save_ei != NULL) {
-    new_ei = vim_strnsave(p_ei, (int)(STRLEN(p_ei) + STRLEN(what)));
-    if (new_ei != NULL) {
-      if (*what == ',' && *p_ei == NUL)
-        STRCPY(new_ei, what + 1);
-      else
-        STRCAT(new_ei, what);
-      set_string_option_direct((char_u *)"ei", -1, new_ei,
-          OPT_FREE, SID_NONE);
-      free(new_ei);
-    }
-  }
+  new_ei = vim_strnsave(p_ei, (int)(STRLEN(p_ei) + STRLEN(what)));
+  if (*what == ',' && *p_ei == NUL)
+    STRCPY(new_ei, what + 1);
+  else
+    STRCAT(new_ei, what);
+  set_string_option_direct((char_u *)"ei", -1, new_ei, OPT_FREE, SID_NONE);
+  free(new_ei);
+
   return save_ei;
 }
 
@@ -6404,7 +6396,7 @@ void do_autocmd(char_u *arg, int forceit)
  * Find the group ID in a ":autocmd" or ":doautocmd" argument.
  * The "argp" argument is advanced to the following argument.
  *
- * Returns the group ID, AUGROUP_ERROR for error (out of memory).
+ * Returns the group ID or AUGROUP_ALL.
  */
 static int au_get_grouparg(char_u **argp)
 {
@@ -6416,8 +6408,6 @@ static int au_get_grouparg(char_u **argp)
   p = skiptowhite(arg);
   if (p > arg) {
     group_name = vim_strnsave(arg, (int)(p - arg));
-    if (group_name == NULL)             /* out of memory */
-      return AUGROUP_ERROR;
     group = au_find_group(group_name);
     if (group == AUGROUP_ERROR)
       group = AUGROUP_ALL;              /* no match, use all groups */
@@ -6587,10 +6577,6 @@ static int do_autocmd_event(event_T event, char_u *pat, int nested, char_u *cmd,
         ap = (AutoPat *)alloc((unsigned)sizeof(AutoPat));
         ap->pat = vim_strnsave(pat, patlen);
         ap->patlen = patlen;
-        if (ap->pat == NULL) {
-          free(ap);
-          return FAIL;
-        }
 
         if (is_buflocal) {
           ap->buflocal_nr = buflocal_nr;
@@ -6628,10 +6614,6 @@ static int do_autocmd_event(event_T event, char_u *pat, int nested, char_u *cmd,
       ac = (AutoCmd *)alloc((unsigned)sizeof(AutoCmd));
       ac->cmd = vim_strsave(cmd);
       ac->scriptID = current_SID;
-      if (ac->cmd == NULL) {
-        free(ac);
-        return FAIL;
-      }
       ac->next = NULL;
       *prev_ac = ac;
       ac->nested = nested;
@@ -7542,8 +7524,7 @@ int has_autocmd(event_T event, char_u *sfname, buf_T *buf)
    * autocommand patterns portable between Unix and MS-DOS.
    */
   sfname = vim_strsave(sfname);
-  if (sfname != NULL)
-    forward_slash(sfname);
+  forward_slash(sfname);
   forward_slash(fname);
 #endif
 
@@ -7681,8 +7662,6 @@ int au_exists(char_u *arg)
 
   /* Make a copy so that we can change the '#' chars to a NUL. */
   arg_save = vim_strsave(arg);
-  if (arg_save == NULL)
-    return FALSE;
   p = vim_strchr(arg_save, '#');
   if (p != NULL)
     *p++ = NUL;
diff --git a/src/nvim/getchar.c b/src/nvim/getchar.c
index efa63f2682..440349ff1b 100644
--- a/src/nvim/getchar.c
+++ b/src/nvim/getchar.c
@@ -2636,7 +2636,6 @@ do_map (
   char_u      *p;
   int n;
   int len = 0;                  /* init for GCC */
-  char_u      *newstr;
   int hasarg;
   int haskey;
   int did_it = FALSE;
@@ -2979,13 +2978,8 @@ do_map (
             } else {                          /* new rhs for existing entry */
               mp->m_mode &= ~mode;                      /* remove mode bits */
               if (mp->m_mode == 0 && !did_it) {             /* reuse entry */
-                newstr = vim_strsave(rhs);
-                if (newstr == NULL) {
-                  retval = 4;                           /* no mem */
-                  goto theend;
-                }
                 free(mp->m_str);
-                mp->m_str = newstr;
+                mp->m_str = vim_strsave(rhs);
                 free(mp->m_orig_str);
                 mp->m_orig_str = vim_strsave(orig_rhs);
                 mp->m_noremap = noremap;
@@ -3057,14 +3051,6 @@ do_map (
   mp->m_keys = vim_strsave(keys);
   mp->m_str = vim_strsave(rhs);
   mp->m_orig_str = vim_strsave(orig_rhs);
-  if (mp->m_keys == NULL || mp->m_str == NULL) {
-    free(mp->m_keys);
-    free(mp->m_str);
-    free(mp->m_orig_str);
-    free(mp);
-    retval = 4;         /* no mem */
-    goto theend;
-  }
   mp->m_keylen = (int)STRLEN(mp->m_keys);
   mp->m_noremap = noremap;
   mp->m_nowait = nowait;
@@ -3328,11 +3314,9 @@ showmap (
     /* Remove escaping of CSI, because "m_str" is in a format to be used
      * as typeahead. */
     char_u *s = vim_strsave(mp->m_str);
-    if (s != NULL) {
-      vim_unescape_csi(s);
-      msg_outtrans_special(s, FALSE);
-      free(s);
-    }
+    vim_unescape_csi(s);
+    msg_outtrans_special(s, FALSE);
+    free(s);
   }
   if (p_verbose > 0)
     last_set_msg(mp->m_script_ID);
@@ -3778,8 +3762,6 @@ eval_map_expr (
   /* Remove escaping of CSI, because "str" is in a format to be used as
    * typeahead. */
   expr = vim_strsave(str);
-  if (expr == NULL)
-    return NULL;
   vim_unescape_csi(expr);
 
   save_cmd = save_cmdline_alloc();
@@ -4325,10 +4307,8 @@ void add_map(char_u *map, int mode)
 
   p_cpo = (char_u *)"";         /* Allow <> notation */
   s = vim_strsave(map);
-  if (s != NULL) {
-    (void)do_map(0, s, mode, FALSE);
-    free(s);
-  }
+  (void)do_map(0, s, mode, FALSE);
+  free(s);
   p_cpo = cpo_save;
 }
 #endif
diff --git a/src/nvim/if_cscope.c b/src/nvim/if_cscope.c
index 8b52fb521f..4e08f08bc0 100644
--- a/src/nvim/if_cscope.c
+++ b/src/nvim/if_cscope.c
@@ -1633,10 +1633,7 @@ static void cs_fill_results(char *tagstr, int totmatches, int *nummatches_a, cha
       if (strcmp(cntx, "<global>") == 0)
         cntxts[totsofar] = NULL;
       else {
-        /* note: if vim_strsave returns NULL, then the context
-         * will be "<global>", which is misleading.
-         */
-        cntxts[totsofar] = (char *)vim_strsave((char_u *)cntx);
+        cntxts[totsofar] = xstrdup(cntx);
       }
 
       totsofar++;
@@ -2110,7 +2107,7 @@ static char *cs_resolve_file(int i, char *name)
      * cscope output. */
     fullname = (char *)concat_fnames(csdir, (char_u *)name, TRUE);
   } else {
-    fullname = (char *)vim_strsave((char_u *)name);
+    fullname = xstrdup(name);
   }
 
   free(csdir);
diff --git a/src/nvim/main.c b/src/nvim/main.c
index 16a155fa20..c263799a7e 100644
--- a/src/nvim/main.c
+++ b/src/nvim/main.c
@@ -1428,8 +1428,8 @@ scripterror:
 
       /* Add the file to the global argument list. */
       ga_grow(&global_alist.al_ga, 1);
-      if ((p = vim_strsave((char_u *)argv[0])) == NULL)
-        mch_exit(2);
+      p = vim_strsave((char_u *)argv[0]);
+
       if (parmp->diff_mode && os_isdir(p) && GARGCOUNT > 0
           && !os_isdir(alist_name(&GARGLIST[0]))) {
         char_u      *r;
diff --git a/src/nvim/mark.c b/src/nvim/mark.c
index 16d360d093..28e8421ef1 100644
--- a/src/nvim/mark.c
+++ b/src/nvim/mark.c
@@ -606,8 +606,7 @@ static char_u *mark_line(pos_T *mp, int lead_len)
   if (mp->lnum == 0 || mp->lnum > curbuf->b_ml.ml_line_count)
     return vim_strsave((char_u *)"-invalid-");
   s = vim_strnsave(skipwhite(ml_get(mp->lnum)), (int)Columns);
-  if (s == NULL)
-    return NULL;
+
   /* Truncate the line to fit it in the window */
   len = 0;
   for (p = s; *p != NUL; mb_ptr_adv(p)) {
diff --git a/src/nvim/memline.c b/src/nvim/memline.c
index 28f3f2a9cc..8c78a78b29 100644
--- a/src/nvim/memline.c
+++ b/src/nvim/memline.c
@@ -2607,8 +2607,8 @@ int ml_replace(linenr_T lnum, char_u *line, int copy)
   if (curbuf->b_ml.ml_mfp == NULL && open_buffer(FALSE, NULL, 0) == FAIL)
     return FAIL;
 
-  if (copy && (line = vim_strsave(line)) == NULL)   /* allocate memory */
-    return FAIL;
+  if (copy)
+    line = vim_strsave(line);
   if (curbuf->b_ml.ml_line_lnum != lnum)            /* other line buffered */
     ml_flush_line(curbuf);                          /* flush it */
   else if (curbuf->b_ml.ml_flags & ML_LINE_DIRTY)   /* same line allocated */
diff --git a/src/nvim/memory.c b/src/nvim/memory.c
index b39c113f99..b609232727 100644
--- a/src/nvim/memory.c
+++ b/src/nvim/memory.c
@@ -192,7 +192,7 @@ char *xstpncpy(char *restrict dst, const char *restrict src, size_t maxlen)
     }
 }
 
-char * xstrdup(const char *str)
+char *xstrdup(const char *str)
 {
   char *ret = strdup(str);
 
diff --git a/src/nvim/menu.c b/src/nvim/menu.c
index 7fa813c5b3..a5ae62eb44 100644
--- a/src/nvim/menu.c
+++ b/src/nvim/menu.c
@@ -308,8 +308,6 @@ add_menu_path (
 
   /* Make a copy so we can stuff around with it, since it could be const */
   path_name = vim_strsave(menu_path);
-  if (path_name == NULL)
-    return FAIL;
   menup = &root_menu;
   parent = NULL;
   name = path_name;
@@ -728,8 +726,6 @@ static int show_menus(char_u *path_name, int modes)
 
   menu = root_menu;
   name = path_name = vim_strsave(path_name);
-  if (path_name == NULL)
-    return FAIL;
 
   /* First, find the (sub)menu with the given name */
   while (*name) {
@@ -1168,7 +1164,7 @@ get_menu_cmd_modes (
 
 /*
  * Modify a menu name starting with "PopUp" to include the mode character.
- * Returns the name in allocated memory (NULL for failure).
+ * Returns the name in allocated memory.
  */
 static char_u *popup_mode_name(char_u *name, int idx)
 {
@@ -1176,10 +1172,9 @@ static char_u *popup_mode_name(char_u *name, int idx)
   int len = (int)STRLEN(name);
 
   p = vim_strnsave(name, len + 1);
-  if (p != NULL) {
-    memmove(p + 6, p + 5, (size_t)(len - 4));
-    p[5] = menu_mode_chars[idx];
-  }
+  memmove(p + 6, p + 5, (size_t)(len - 4));
+  p[5] = menu_mode_chars[idx];
+
   return p;
 }
 
@@ -1305,8 +1300,6 @@ void ex_emenu(exarg_T *eap)
   char_u      *mode;
 
   saved_name = vim_strsave(eap->arg);
-  if (saved_name == NULL)
-    return;
 
   menu = root_menu;
   name = saved_name;
@@ -1419,8 +1412,6 @@ vimmenu_T *gui_find_menu(char_u *path_name)
   menu = root_menu;
 
   saved_name = vim_strsave(path_name);
-  if (saved_name == NULL)
-    return NULL;
 
   name = saved_name;
   while (*name) {
@@ -1513,23 +1504,21 @@ void ex_menutranslate(exarg_T *eap)
       ga_grow(&menutrans_ga, 1);
       tp = (menutrans_T *)menutrans_ga.ga_data;
       from = vim_strsave(from);
-      if (from != NULL) {
-        from_noamp = menu_text(from, NULL, NULL);
-        to = vim_strnsave(to, (int)(arg - to));
-        if (from_noamp != NULL && to != NULL) {
-          menu_translate_tab_and_shift(from);
-          menu_translate_tab_and_shift(to);
-          menu_unescape_name(from);
-          menu_unescape_name(to);
-          tp[menutrans_ga.ga_len].from = from;
-          tp[menutrans_ga.ga_len].from_noamp = from_noamp;
-          tp[menutrans_ga.ga_len].to = to;
-          ++menutrans_ga.ga_len;
-        } else {
-          free(from);
-          free(from_noamp);
-          free(to);
-        }
+      from_noamp = menu_text(from, NULL, NULL);
+      to = vim_strnsave(to, (int)(arg - to));
+      if (from_noamp != NULL) {
+        menu_translate_tab_and_shift(from);
+        menu_translate_tab_and_shift(to);
+        menu_unescape_name(from);
+        menu_unescape_name(to);
+        tp[menutrans_ga.ga_len].from = from;
+        tp[menutrans_ga.ga_len].from_noamp = from_noamp;
+        tp[menutrans_ga.ga_len].to = to;
+        ++menutrans_ga.ga_len;
+      } else {
+        free(from);
+        free(from_noamp);
+        free(to);
       }
     }
   }
diff --git a/src/nvim/misc1.c b/src/nvim/misc1.c
index 4f7a78e534..df286c3a07 100644
--- a/src/nvim/misc1.c
+++ b/src/nvim/misc1.c
@@ -120,8 +120,6 @@ open_line (
    * make a copy of the current line so we can mess with it
    */
   saved_line = vim_strsave(ml_get_curline());
-  if (saved_line == NULL)           /* out of memory! */
-    return FALSE;
 
   if (State & VREPLACE_FLAG) {
     /*
@@ -137,8 +135,6 @@ open_line (
       next_line = vim_strsave(ml_get(curwin->w_cursor.lnum + 1));
     else
       next_line = vim_strsave((char_u *)"");
-    if (next_line == NULL)          /* out of memory! */
-      goto theend;
 
     /*
      * In VREPLACE mode, a NL replaces the rest of the line, and starts
@@ -918,8 +914,6 @@ open_line (
   if (State & VREPLACE_FLAG) {
     /* Put new line in p_extra */
     p_extra = vim_strsave(ml_get_curline());
-    if (p_extra == NULL)
-      goto theend;
 
     /* Put back original line */
     ml_replace(curwin->w_cursor.lnum, next_line, FALSE);
@@ -1743,9 +1737,6 @@ truncate_line (
   else
     newp = vim_strnsave(ml_get(lnum), col);
 
-  if (newp == NULL)
-    return FAIL;
-
   ml_replace(lnum, newp, FALSE);
 
   /* mark the buffer as changed and prepare for displaying */
@@ -2874,13 +2865,11 @@ expand_env_esc (
       if (p_ssl && var != NULL && vim_strchr(var, '\\') != NULL) {
         char_u  *p = vim_strsave(var);
 
-        if (p != NULL) {
-          if (mustfree)
-            free(var);
-          var = p;
-          mustfree = TRUE;
-          forward_slash(var);
-        }
+        if (mustfree)
+          free(var);
+        var = p;
+        mustfree = TRUE;
+        forward_slash(var);
       }
 #endif
 
@@ -3033,7 +3022,7 @@ char_u *vim_getenv(char_u *name, int *mustfree)
       /* check that the result is a directory name */
       p = vim_strnsave(p, (int)(pend - p));
 
-      if (p != NULL && !os_isdir(p)) {
+      if (!os_isdir(p)) {
         free(p);
         p = NULL;
       } else {
diff --git a/src/nvim/ops.c b/src/nvim/ops.c
index dff9822dd0..dd5314e571 100644
--- a/src/nvim/ops.c
+++ b/src/nvim/ops.c
@@ -689,8 +689,6 @@ char_u *get_expr_line(void)
   /* Make a copy of the expression, because evaluating it may cause it to be
    * changed. */
   expr_copy = vim_strsave(expr_line);
-  if (expr_copy == NULL)
-    return NULL;
 
   /* When we are invoked recursively limit the evaluation to 10 levels.
    * Then return the string as-is. */
@@ -2154,17 +2152,15 @@ void op_insert(oparg_T *oap, long count1)
     if (pre_textlen >= 0
         && (ins_len = (long)STRLEN(firstline) - pre_textlen) > 0) {
       ins_text = vim_strnsave(firstline, (int)ins_len);
-      if (ins_text != NULL) {
-        /* block handled here */
-        if (u_save(oap->start.lnum,
-                (linenr_T)(oap->end.lnum + 1)) == OK)
-          block_insert(oap, ins_text, (oap->op_type == OP_INSERT),
-              &bd);
-
-        curwin->w_cursor.col = oap->start.col;
-        check_cursor();
-        free(ins_text);
-      }
+      /* block handled here */
+      if (u_save(oap->start.lnum,
+              (linenr_T)(oap->end.lnum + 1)) == OK)
+        block_insert(oap, ins_text, (oap->op_type == OP_INSERT),
+            &bd);
+
+      curwin->w_cursor.col = oap->start.col;
+      check_cursor();
+      free(ins_text);
     }
   }
 }
@@ -2414,9 +2410,7 @@ int op_yank(oparg_T *oap, int deleting, int mess)
       break;
 
     case MLINE:
-      if ((y_current->y_array[y_idx] =
-             vim_strsave(ml_get(lnum))) == NULL)
-        goto fail;
+      y_current->y_array[y_idx] = vim_strsave(ml_get(lnum));
       break;
 
     case MCHAR:
@@ -2547,13 +2541,7 @@ int op_yank(oparg_T *oap, int deleting, int mess)
     curbuf->b_op_end.col = MAXCOL;
   }
 
-
   return OK;
-
-fail:           /* free the allocated lines */
-  free_yank(y_idx + 1);
-  y_current = curr;
-  return FAIL;
 }
 
 static void yank_copy_line(struct block_def *bd, long y_idx)
@@ -2699,14 +2687,10 @@ do_put (
       if (u_save_cursor() == FAIL)
         goto end;
       ptr = vim_strsave(ml_get_cursor());
-      if (ptr == NULL)
-        goto end;
       ml_append(curwin->w_cursor.lnum, ptr, (colnr_T)0, FALSE);
       free(ptr);
 
       ptr = vim_strnsave(ml_get_curline(), curwin->w_cursor.col);
-      if (ptr == NULL)
-        goto end;
       ml_replace(curwin->w_cursor.lnum, ptr, FALSE);
       ++nr_lines;
       dir = FORWARD;
@@ -3628,20 +3612,19 @@ static int same_leader(linenr_T lnum, int leader1_len, char_u *leader1_flags, in
    * The first line has to be saved, only one line can be locked at a time.
    */
   line1 = vim_strsave(ml_get(lnum));
-  if (line1 != NULL) {
-    for (idx1 = 0; vim_iswhite(line1[idx1]); ++idx1)
-      ;
-    line2 = ml_get(lnum + 1);
-    for (idx2 = 0; idx2 < leader2_len; ++idx2) {
-      if (!vim_iswhite(line2[idx2])) {
-        if (line1[idx1++] != line2[idx2])
-          break;
-      } else
-        while (vim_iswhite(line1[idx1]))
-          ++idx1;
-    }
-    free(line1);
+  for (idx1 = 0; vim_iswhite(line1[idx1]); ++idx1)
+    ;
+  line2 = ml_get(lnum + 1);
+  for (idx2 = 0; idx2 < leader2_len; ++idx2) {
+    if (!vim_iswhite(line2[idx2])) {
+      if (line1[idx1++] != line2[idx2])
+        break;
+    } else
+      while (vim_iswhite(line1[idx1]))
+        ++idx1;
   }
+  free(line1);
+
   return idx2 == leader2_len && idx1 == leader1_len;
 }
 
@@ -4773,8 +4756,7 @@ void write_reg_contents_ex(int name, char_u *str, int maxlen, int must_append, i
     char_u      *p, *s;
 
     p = vim_strnsave(str, (int)len);
-    if (p == NULL)
-      return;
+
     if (must_append) {
       s = concat_str(get_expr_line_src(), p);
       free(p);
diff --git a/src/nvim/option.c b/src/nvim/option.c
index b5f480870e..0ac2a49621 100644
--- a/src/nvim/option.c
+++ b/src/nvim/option.c
@@ -2102,7 +2102,8 @@ void set_init_1(void)
       p = (char_u *)_(*(char **)options[opt_idx].var);
     else
       p = option_expand(opt_idx, NULL);
-    if (p != NULL && (p = vim_strsave(p)) != NULL) {
+    if (p != NULL) {
+      p = vim_strsave(p);
       *(char_u **)options[opt_idx].var = p;
       /* VIMEXP
        * Defaults for all expanded options are currently the same for Vi
@@ -2291,14 +2292,12 @@ void set_string_default(char *name, char_u *val)
   int opt_idx;
 
   p = vim_strsave(val);
-  if (p != NULL) {              /* we don't want a NULL */
-    opt_idx = findoption((char_u *)name);
-    if (opt_idx >= 0) {
-      if (options[opt_idx].flags & P_DEF_ALLOCED)
-        free(options[opt_idx].def_val[VI_DEFAULT]);
-      options[opt_idx].def_val[VI_DEFAULT] = p;
-      options[opt_idx].flags |= P_DEF_ALLOCED;
-    }
+  opt_idx = findoption((char_u *)name);
+  if (opt_idx >= 0) {
+    if (options[opt_idx].flags & P_DEF_ALLOCED)
+      free(options[opt_idx].def_val[VI_DEFAULT]);
+    options[opt_idx].def_val[VI_DEFAULT] = p;
+    options[opt_idx].flags |= P_DEF_ALLOCED;
   }
 }
 
@@ -2463,7 +2462,7 @@ void set_init_3(void)
         p1 = p2 + 1;
     p = vim_strnsave(p1, (int)(p - p1));
   }
-  if (p != NULL) {
+  {
     /*
      * Default for p_sp is "| tee", for p_srr is ">".
      * For known shells it is changed here to include stderr.
@@ -2519,16 +2518,12 @@ void set_helplang_default(char_u *lang)
     if (options[idx].flags & P_ALLOCED)
       free_string_option(p_hlg);
     p_hlg = vim_strsave(lang);
-    if (p_hlg == NULL)
-      p_hlg = empty_option;
-    else {
-      /* zh_CN becomes "cn", zh_TW becomes "tw". */
-      if (STRNICMP(p_hlg, "zh_", 3) == 0 && STRLEN(p_hlg) >= 5) {
-        p_hlg[0] = TOLOWER_ASC(p_hlg[3]);
-        p_hlg[1] = TOLOWER_ASC(p_hlg[4]);
-      }
-      p_hlg[2] = NUL;
+    /* zh_CN becomes "cn", zh_TW becomes "tw". */
+    if (STRNICMP(p_hlg, "zh_", 3) == 0 && STRLEN(p_hlg) >= 5) {
+      p_hlg[0] = TOLOWER_ASC(p_hlg[3]);
+      p_hlg[1] = TOLOWER_ASC(p_hlg[4]);
     }
+    p_hlg[2] = NUL;
     options[idx].flags |= P_ALLOCED;
   }
 }
@@ -3754,7 +3749,7 @@ set_string_option_direct (
     return;
 
   s = vim_strsave(val);
-  if (s != NULL) {
+  {
     varp = (char_u **)get_varp_scope(&(options[idx]),
         both ? OPT_LOCAL : opt_flags);
     if ((opt_flags & OPT_FREE) && (options[idx].flags & P_ALLOCED))
@@ -3795,9 +3790,8 @@ set_string_option_global (
     p = (char_u **)GLOBAL_WO(varp);
   else
     p = (char_u **)options[opt_idx].var;
-  if (options[opt_idx].indir != PV_NONE
-      && p != varp
-      && (s = vim_strsave(*varp)) != NULL) {
+  if (options[opt_idx].indir != PV_NONE && p != varp) {
+    s = vim_strsave(*varp);
     free_string_option(*p);
     *p = s;
   }
@@ -3824,18 +3818,17 @@ set_string_option (
     return NULL;
 
   s = vim_strsave(value);
-  if (s != NULL) {
-    varp = (char_u **)get_varp_scope(&(options[opt_idx]),
-        (opt_flags & (OPT_LOCAL | OPT_GLOBAL)) == 0
-        ? (((int)options[opt_idx].indir & PV_BOTH)
-           ? OPT_GLOBAL : OPT_LOCAL)
-        : opt_flags);
-    oldval = *varp;
-    *varp = s;
-    if ((r = did_set_string_option(opt_idx, varp, TRUE, oldval, NULL,
-             opt_flags)) == NULL)
-      did_set_option(opt_idx, opt_flags, TRUE);
-  }
+  varp = (char_u **)get_varp_scope(&(options[opt_idx]),
+      (opt_flags & (OPT_LOCAL | OPT_GLOBAL)) == 0
+      ? (((int)options[opt_idx].indir & PV_BOTH)
+        ? OPT_GLOBAL : OPT_LOCAL)
+      : opt_flags);
+  oldval = *varp;
+  *varp = s;
+  if ((r = did_set_string_option(opt_idx, varp, TRUE, oldval, NULL,
+          opt_flags)) == NULL)
+    did_set_option(opt_idx, opt_flags, TRUE);
+
   return r;
 }
 
diff --git a/src/nvim/os/users.c b/src/nvim/os/users.c
index 1b302098dd..e1faacb8ac 100644
--- a/src/nvim/os/users.c
+++ b/src/nvim/os/users.c
@@ -28,10 +28,7 @@ int os_get_usernames(garray_T *users)
     // pw->pw_name shouldn't be NULL but just in case...
     if (pw->pw_name != NULL) {
       ga_grow(users, 1);
-      user = (char *)vim_strsave((char_u*)pw->pw_name);
-      if (user == NULL) {
-        return FAIL;
-      }
+      user = xstrdup(pw->pw_name);
       ((char **)(users->ga_data))[users->ga_len++] = user;
     }
   }
@@ -79,8 +76,7 @@ char *os_get_user_directory(const char *name)
   pw = getpwnam(name);
   if (pw != NULL) {
     // save the string from the static passwd entry into malloced memory
-    char *user_directory = (char *)vim_strsave((char_u *)pw->pw_dir);
-    return user_directory;
+    return vim_strsave(pw->pw_dir);
   }
 #endif
   return NULL;
diff --git a/src/nvim/os_unix.c b/src/nvim/os_unix.c
index 1669a7cf77..cc0d9197ef 100644
--- a/src/nvim/os_unix.c
+++ b/src/nvim/os_unix.c
@@ -1437,10 +1437,9 @@ char_u      ***file;
 
   for (i = 0; i < num_pat; i++) {
     s = vim_strsave(pat[i]);
-    if (s != NULL)
-      /* Be compatible with expand_filename(): halve the number of
-       * backslashes. */
-      backslash_halve(s);
+    /* Be compatible with expand_filename(): halve the number of
+     * backslashes. */
+    backslash_halve(s);
     (*file)[i] = s;
   }
   *num_file = num_pat;
diff --git a/src/nvim/path.c b/src/nvim/path.c
index 7a3c644499..852ac62d71 100644
--- a/src/nvim/path.c
+++ b/src/nvim/path.c
@@ -296,7 +296,7 @@ void add_pathsep(char_u *p)
 
 /*
  * FullName_save - Make an allocated copy of a full file name.
- * Returns NULL when out of memory.
+ * Returns NULL when fname is NULL.
  */
 char_u *
 FullName_save (
@@ -305,20 +305,19 @@ FullName_save (
                                  * like a full path name */
 )
 {
-  char_u      *buf;
   char_u      *new_fname = NULL;
 
   if (fname == NULL)
     return NULL;
 
-  buf = alloc((unsigned)MAXPATHL);
-  if (buf != NULL) {
-    if (vim_FullName(fname, buf, MAXPATHL, force) != FAIL)
-      new_fname = vim_strsave(buf);
-    else
-      new_fname = vim_strsave(fname);
-    free(buf);
-  }
+  char_u *buf = xmalloc(MAXPATHL);
+
+  if (vim_FullName(fname, buf, MAXPATHL, force) != FAIL)
+    new_fname = vim_strsave(buf);
+  else
+    new_fname = vim_strsave(fname);
+  free(buf);
+
   return new_fname;
 }
 
@@ -650,8 +649,6 @@ static void expand_path_option(char_u *curdir, garray_T *gap)
     ga_grow(gap, 1);
 
     p = vim_strsave(buf);
-    if (p == NULL)
-      break;
     ((char_u **)gap->ga_data)[gap->ga_len++] = p;
   }
 
@@ -1137,8 +1134,6 @@ expand_backtick (
 
   /* Create the command: lop off the backticks. */
   cmd = vim_strnsave(pat + 1, (int)STRLEN(pat) - 2);
-  if (cmd == NULL)
-    return 0;
 
   if (*cmd == '=')          /* `={expr}`: Expand expression */
     buffer = eval_to_string(cmd + 1, &p, TRUE);
@@ -1563,9 +1558,7 @@ char_u *fix_fname(char_u *fname)
   fname = vim_strsave(fname);
 
 # ifdef USE_FNAME_CASE
-  if (fname != NULL) {
-    fname_case(fname, 0);             /* set correct case for file name */
-  }
+  fname_case(fname, 0);  // set correct case for file name
 # endif
 
   return fname;
diff --git a/src/nvim/quickfix.c b/src/nvim/quickfix.c
index 299a0a38db..0e6ed67351 100644
--- a/src/nvim/quickfix.c
+++ b/src/nvim/quickfix.c
@@ -929,19 +929,14 @@ qf_add_entry (
     qfp->qf_fnum = bufnum;
   else
     qfp->qf_fnum = qf_get_fnum(dir, fname);
-  if ((qfp->qf_text = vim_strsave(mesg)) == NULL) {
-    free(qfp);
-    return FAIL;
-  }
+  qfp->qf_text = vim_strsave(mesg);
   qfp->qf_lnum = lnum;
   qfp->qf_col = col;
   qfp->qf_viscol = vis_col;
-  if (pattern == NULL || *pattern == NUL)
+  if (pattern == NULL || *pattern == NUL) {
     qfp->qf_pattern = NULL;
-  else if ((qfp->qf_pattern = vim_strsave(pattern)) == NULL) {
-    free(qfp->qf_text);
-    free(qfp);
-    return FAIL;
+  } else {
+    qfp->qf_pattern = vim_strsave(pattern);
   }
   qfp->qf_nr = nr;
   if (type != 1 && !vim_isprintc(type))   /* only printable chars allowed */
diff --git a/src/nvim/regexp.c b/src/nvim/regexp.c
index cade4bd1c1..f7e278a4fe 100644
--- a/src/nvim/regexp.c
+++ b/src/nvim/regexp.c
@@ -1141,8 +1141,7 @@ char_u *skip_regexp(char_u *startp, int dirc, int magic, char_u **newp)
         /* change "\?" to "?", make a copy first. */
         if (*newp == NULL) {
           *newp = vim_strsave(startp);
-          if (*newp != NULL)
-            p = *newp + (p - startp);
+          p = *newp + (p - startp);
         }
         if (*newp != NULL)
           STRMOVE(p, p + 1);
diff --git a/src/nvim/spell.c b/src/nvim/spell.c
index 0f35681546..b2f2bf6944 100644
--- a/src/nvim/spell.c
+++ b/src/nvim/spell.c
@@ -2479,8 +2479,6 @@ spell_load_file (
 
     // Remember the file name, used to reload the file when it's updated.
     lp->sl_fname = vim_strsave(fname);
-    if (lp->sl_fname == NULL)
-      goto endFAIL;
 
     // Check for .add.spl.
     lp->sl_add = strstr((char *)path_tail(fname), SPL_FNAME_ADD) != NULL;
@@ -3669,8 +3667,6 @@ char_u *did_set_spelllang(win_T *wp)
   // Make a copy of 'spelllang', the SpellFileMissing autocommands may change
   // it under our fingers.
   spl_copy = vim_strsave(wp->w_s->b_p_spl);
-  if (spl_copy == NULL)
-    goto theend;
 
   wp->w_s->b_cjk = 0;
 
@@ -3936,11 +3932,9 @@ static void use_midword(slang_T *lp, win_T *wp)
         // Append multi-byte chars to "b_spell_ismw_mb".
         n = (int)STRLEN(wp->w_s->b_spell_ismw_mb);
         bp = vim_strnsave(wp->w_s->b_spell_ismw_mb, n + l);
-        if (bp != NULL) {
-          free(wp->w_s->b_spell_ismw_mb);
-          wp->w_s->b_spell_ismw_mb = bp;
-          vim_strncpy(bp + n, p, l);
-        }
+        free(wp->w_s->b_spell_ismw_mb);
+        wp->w_s->b_spell_ismw_mb = bp;
+        vim_strncpy(bp + n, p, l);
       }
       p += l;
     } else
@@ -5175,8 +5169,6 @@ static afffile_T *spell_read_aff(spellinfo_T *spin, char_u *fname)
           if (HASHITEM_EMPTY(hash_find(&spin->si_commonwords,
                       items[i]))) {
             p = vim_strsave(items[i]);
-            if (p == NULL)
-              break;
             hash_add(&spin->si_commonwords, p);
           }
         }
@@ -8679,8 +8671,6 @@ void spell_suggest(int count)
 
   // Make a copy of current line since autocommands may free the line.
   line = vim_strsave(ml_get_curline());
-  if (line == NULL)
-    goto skip;
 
   // Get the list of suggestions.  Limit to 'lines' - 2 or the number in
   // 'spellsuggest', whatever is smaller.
@@ -8819,8 +8809,6 @@ void spell_suggest(int count)
     curwin->w_cursor = prev_cursor;
 
   spell_find_cleanup(&sug);
-skip:
-  free(line);
 }
 
 // Check if the word at line "lnum" column "col" is required to start with a
@@ -9064,8 +9052,6 @@ spell_find_suggest (
 
   // Make a copy of 'spellsuggest', because the expression may change it.
   sps_copy = vim_strsave(p_sps);
-  if (sps_copy == NULL)
-    return;
 
   // Loop over the items in 'spellsuggest'.
   for (p = sps_copy; *p != NUL; ) {
@@ -11025,13 +11011,11 @@ static void score_comp_sal(suginfo_T *su)
           // Add the suggestion.
           sstp = &SUG(su->su_sga, su->su_sga.ga_len);
           sstp->st_word = vim_strsave(stp->st_word);
-          if (sstp->st_word != NULL) {
-            sstp->st_wordlen = stp->st_wordlen;
-            sstp->st_score = score;
-            sstp->st_altscore = 0;
-            sstp->st_orglen = stp->st_orglen;
-            ++su->su_sga.ga_len;
-          }
+          sstp->st_wordlen = stp->st_wordlen;
+          sstp->st_score = score;
+          sstp->st_altscore = 0;
+          sstp->st_orglen = stp->st_orglen;
+          ++su->su_sga.ga_len;
         }
       }
       break;
@@ -11731,25 +11715,23 @@ add_suggestion (
     // Add a suggestion.
     stp = &SUG(*gap, gap->ga_len);
     stp->st_word = vim_strnsave(goodword, goodlen);
-    if (stp->st_word != NULL) {
-      stp->st_wordlen = goodlen;
-      stp->st_score = score;
-      stp->st_altscore = altscore;
-      stp->st_had_bonus = had_bonus;
-      stp->st_orglen = badlen;
-      stp->st_slang = slang;
-      ++gap->ga_len;
-
-      // If we have too many suggestions now, sort the list and keep
-      // the best suggestions.
-      if (gap->ga_len > SUG_MAX_COUNT(su)) {
-        if (maxsf)
-          su->su_sfmaxscore = cleanup_suggestions(gap,
-              su->su_sfmaxscore, SUG_CLEAN_COUNT(su));
-        else
-          su->su_maxscore = cleanup_suggestions(gap,
-              su->su_maxscore, SUG_CLEAN_COUNT(su));
-      }
+    stp->st_wordlen = goodlen;
+    stp->st_score = score;
+    stp->st_altscore = altscore;
+    stp->st_had_bonus = had_bonus;
+    stp->st_orglen = badlen;
+    stp->st_slang = slang;
+    ++gap->ga_len;
+
+    // If we have too many suggestions now, sort the list and keep
+    // the best suggestions.
+    if (gap->ga_len > SUG_MAX_COUNT(su)) {
+      if (maxsf)
+        su->su_sfmaxscore = cleanup_suggestions(gap,
+            su->su_sfmaxscore, SUG_CLEAN_COUNT(su));
+      else
+        su->su_maxscore = cleanup_suggestions(gap,
+            su->su_maxscore, SUG_CLEAN_COUNT(su));
     }
   }
 }
@@ -11800,8 +11782,7 @@ static void add_banned(suginfo_T *su, char_u *word)
   hi = hash_lookup(&su->su_banned, word, hash);
   if (HASHITEM_EMPTY(hi)) {
     s = vim_strsave(word);
-    if (s != NULL)
-      hash_add_item(&su->su_banned, hi, s, hash);
+    hash_add_item(&su->su_banned, hi, s, hash);
   }
 }
 
diff --git a/src/nvim/strings.c b/src/nvim/strings.c
index 731afa4452..1cadc5df09 100644
--- a/src/nvim/strings.c
+++ b/src/nvim/strings.c
@@ -242,49 +242,45 @@ void vim_strup(char_u *p)
 /*
  * Make string "s" all upper-case and return it in allocated memory.
  * Handles multi-byte characters as well as possible.
- * Returns NULL when out of memory.
  */
 char_u *strup_save(char_u *orig)
 {
-  char_u      *p;
-  char_u      *res;
+  char_u *res = vim_strsave(orig);
 
-  res = p = vim_strsave(orig);
-
-  if (res != NULL)
-    while (*p != NUL) {
-      int l;
-
-      if (enc_utf8) {
-        int c, uc;
-        int newl;
-        char_u  *s;
-
-        c = utf_ptr2char(p);
-        uc = utf_toupper(c);
-
-        /* Reallocate string when byte count changes.  This is rare,
-         * thus it's OK to do another malloc()/free(). */
-        l = utf_ptr2len(p);
-        newl = utf_char2len(uc);
-        if (newl != l) {
-          s = alloc((unsigned)STRLEN(res) + 1 + newl - l);
-          memmove(s, res, p - res);
-          STRCPY(s + (p - res) + newl, p + l);
-          p = s + (p - res);
-          free(res);
-          res = s;
-        }
-
-        utf_char2bytes(uc, p);
-        p += newl;
-      } else if (has_mbyte && (l = (*mb_ptr2len)(p)) > 1)
-        p += l;                 /* skip multi-byte character */
-      else {
-        *p = TOUPPER_LOC(*p);         /* note that toupper() can be a macro */
-        p++;
+  char_u *p = res;
+  while (*p != NUL) {
+    int l;
+
+    if (enc_utf8) {
+      int c, uc;
+      int newl;
+      char_u  *s;
+
+      c = utf_ptr2char(p);
+      uc = utf_toupper(c);
+
+      /* Reallocate string when byte count changes.  This is rare,
+       * thus it's OK to do another malloc()/free(). */
+      l = utf_ptr2len(p);
+      newl = utf_char2len(uc);
+      if (newl != l) {
+        s = alloc((unsigned)STRLEN(res) + 1 + newl - l);
+        memmove(s, res, p - res);
+        STRCPY(s + (p - res) + newl, p + l);
+        p = s + (p - res);
+        free(res);
+        res = s;
       }
+
+      utf_char2bytes(uc, p);
+      p += newl;
+    } else if (has_mbyte && (l = (*mb_ptr2len)(p)) > 1)
+      p += l;                 /* skip multi-byte character */
+    else {
+      *p = TOUPPER_LOC(*p);         /* note that toupper() can be a macro */
+      p++;
     }
+  }
 
   return res;
 }
diff --git a/src/nvim/syntax.c b/src/nvim/syntax.c
index a72bd2bec6..2b1f35d72d 100644
--- a/src/nvim/syntax.c
+++ b/src/nvim/syntax.c
@@ -4113,8 +4113,6 @@ get_syn_options (
         if (gname_start == arg)
           return NULL;
         gname = vim_strnsave(gname_start, (int)(arg - gname_start));
-        if (gname == NULL)
-          return NULL;
         if (STRCMP(gname, "NONE") == 0)
           *opt->sync_idx = NONE_IDX;
         else {
@@ -4823,14 +4821,10 @@ static int syn_scl_name2id(char_u *name)
  */
 static int syn_scl_namen2id(char_u *linep, int len)
 {
-  char_u  *name;
-  int id = 0;
+  char_u *name = vim_strnsave(linep, len);
+  int id = syn_scl_name2id(name);
+  free(name);
 
-  name = vim_strnsave(linep, len);
-  if (name != NULL) {
-    id = syn_scl_name2id(name);
-    free(name);
-  }
   return id;
 }
 
@@ -4846,8 +4840,6 @@ static int syn_check_cluster(char_u *pp, int len)
   char_u      *name;
 
   name = vim_strnsave(pp, len);
-  if (name == NULL)
-    return 0;
 
   id = syn_scl_name2id(name);
   if (id == 0)                          /* doesn't exist yet */
@@ -4996,8 +4988,7 @@ static char_u *get_syn_pattern(char_u *arg, synpat_T *ci)
     return NULL;
   }
   /* store the pattern and compiled regexp program */
-  if ((ci->sp_pattern = vim_strnsave(arg + 1, (int)(end - arg - 1))) == NULL)
-    return NULL;
+  ci->sp_pattern = vim_strnsave(arg + 1, (int)(end - arg - 1));
 
   /* Make 'cpoptions' empty, to avoid the 'l' flag */
   cpo_save = p_cpo;
@@ -5139,11 +5130,8 @@ static void syn_cmd_sync(exarg_T *eap, int syncing)
 
       if (!eap->skip) {
         /* store the pattern and compiled regexp program */
-        if ((curwin->w_s->b_syn_linecont_pat = vim_strnsave(next_arg + 1,
-                 (int)(arg_end - next_arg - 1))) == NULL) {
-          finished = TRUE;
-          break;
-        }
+        curwin->w_s->b_syn_linecont_pat =
+          vim_strnsave(next_arg + 1, (int)(arg_end - next_arg - 1));
         curwin->w_s->b_syn_linecont_ic = curwin->w_s->b_syn_ic;
 
         /* Make 'cpoptions' empty, to avoid the 'l' flag */
@@ -5518,24 +5506,22 @@ void ex_syntax(exarg_T *eap)
   for (subcmd_end = arg; ASCII_ISALPHA(*subcmd_end); ++subcmd_end)
     ;
   subcmd_name = vim_strnsave(arg, (int)(subcmd_end - arg));
-  if (subcmd_name != NULL) {
-    if (eap->skip)              /* skip error messages for all subcommands */
-      ++emsg_skip;
-    for (i = 0;; ++i) {
-      if (subcommands[i].name == NULL) {
-        EMSG2(_("E410: Invalid :syntax subcommand: %s"), subcmd_name);
-        break;
-      }
-      if (STRCMP(subcmd_name, (char_u *)subcommands[i].name) == 0) {
-        eap->arg = skipwhite(subcmd_end);
-        (subcommands[i].func)(eap, FALSE);
-        break;
-      }
+  if (eap->skip)              /* skip error messages for all subcommands */
+    ++emsg_skip;
+  for (i = 0;; ++i) {
+    if (subcommands[i].name == NULL) {
+      EMSG2(_("E410: Invalid :syntax subcommand: %s"), subcmd_name);
+      break;
+    }
+    if (STRCMP(subcmd_name, (char_u *)subcommands[i].name) == 0) {
+      eap->arg = skipwhite(subcmd_end);
+      (subcommands[i].func)(eap, FALSE);
+      break;
     }
-    free(subcmd_name);
-    if (eap->skip)
-      --emsg_skip;
   }
+  free(subcmd_name);
+  if (eap->skip)
+    --emsg_skip;
 }
 
 void ex_ownsyntax(exarg_T *eap)
@@ -6392,10 +6378,6 @@ do_highlight (
         ++linep;
       free(key);
       key = vim_strnsave_up(key_start, (int)(linep - key_start));
-      if (key == NULL) {
-        error = TRUE;
-        break;
-      }
       linep = skipwhite(linep);
 
       if (STRCMP(key, "NONE") == 0) {
@@ -6440,10 +6422,7 @@ do_highlight (
       }
       free(arg);
       arg = vim_strnsave(arg_start, (int)(linep - arg_start));
-      if (arg == NULL) {
-        error = TRUE;
-        break;
-      }
+
       if (*linep == '\'')
         ++linep;
 
@@ -6725,10 +6704,6 @@ do_highlight (
                  arg[off + len] != ','; ++len)
               ;
             tname = vim_strnsave(arg + off, len);
-            if (tname == NULL) {                /* out of memory */
-              error = TRUE;
-              break;
-            }
             /* lookup the escape sequence for the item */
             p = get_term_code(tname);
             free(tname);
@@ -7410,14 +7385,10 @@ char_u *syn_id2name(int id)
  */
 int syn_namen2id(char_u *linep, int len)
 {
-  char_u  *name;
-  int id = 0;
+  char_u *name = vim_strnsave(linep, len);
+  int id = syn_name2id(name);
+  free(name);
 
-  name = vim_strnsave(linep, len);
-  if (name != NULL) {
-    id = syn_name2id(name);
-    free(name);
-  }
   return id;
 }
 
@@ -7433,8 +7404,6 @@ int syn_check_group(char_u *pp, int len)
   char_u  *name;
 
   name = vim_strnsave(pp, len);
-  if (name == NULL)
-    return 0;
 
   id = syn_name2id(name);
   if (id == 0)                          /* doesn't exist yet */
diff --git a/src/nvim/tag.c b/src/nvim/tag.c
index 0e01350537..93358d46e6 100644
--- a/src/nvim/tag.c
+++ b/src/nvim/tag.c
@@ -236,8 +236,7 @@ do_tag (
           cur_fnum = ptag_entry.cur_fnum;
         } else {
           free(ptag_entry.tagname);
-          if ((ptag_entry.tagname = vim_strsave(tag)) == NULL)
-            goto end_do_tag;
+          ptag_entry.tagname = vim_strsave(tag);
         }
       } else {
         /*
@@ -256,13 +255,9 @@ do_tag (
           --tagstackidx;
         }
 
-        /*
-         * put the tag name in the tag stack
-         */
-        if ((tagstack[tagstackidx].tagname = vim_strsave(tag)) == NULL) {
-          curwin->w_tagstacklen = tagstacklen - 1;
-          goto end_do_tag;
-        }
+        // put the tag name in the tag stack
+        tagstack[tagstackidx].tagname = vim_strsave(tag);
+
         curwin->w_tagstacklen = tagstacklen;
 
         save_pos = TRUE;                /* save the cursor position below */
@@ -1211,11 +1206,9 @@ find_tags (
         && ASCII_ISALPHA(pat[orgpat.len - 2])
         && ASCII_ISALPHA(pat[orgpat.len - 1])) {
       saved_pat = vim_strnsave(pat, orgpat.len - 3);
-      if (saved_pat != NULL) {
-        help_lang_find = &pat[orgpat.len - 2];
-        orgpat.pat = saved_pat;
-        orgpat.len -= 3;
-      }
+      help_lang_find = &pat[orgpat.len - 2];
+      orgpat.pat = saved_pat;
+      orgpat.len -= 3;
     }
   }
   if (p_tl != 0 && orgpat.len > p_tl)           /* adjust for 'taglength' */
@@ -2099,8 +2092,6 @@ get_tagfname (
      * the value without notifying us. */
     tnp->tn_tags = vim_strsave((*curbuf->b_p_tags != NUL)
         ? curbuf->b_p_tags : p_tags);
-    if (tnp->tn_tags == NULL)
-      return FAIL;
     tnp->tn_np = tnp->tn_tags;
   }
 
@@ -2435,8 +2426,6 @@ jumpto_tag (
     retval = NOTAGFILE;
     free(nofile_fname);
     nofile_fname = vim_strsave(fname);
-    if (nofile_fname == NULL)
-      nofile_fname = empty_option;
     goto erret;
   }
 
diff --git a/src/nvim/term.c b/src/nvim/term.c
index 7a44b52f36..59f44c9f3e 100644
--- a/src/nvim/term.c
+++ b/src/nvim/term.c
@@ -1198,15 +1198,13 @@ static void parse_builtin_tcap(char_u *term)
           char_u  *s, *t;
 
           s = vim_strsave((char_u *)p->bt_string);
-          if (s != NULL) {
-            for (t = s; *t; ++t)
-              if (term_7to8bit(t)) {
-                *t = term_7to8bit(t);
-                STRCPY(t + 1, t + 2);
-              }
-            term_strings[p->bt_entry] = s;
-            set_term_option_alloced(&term_strings[p->bt_entry]);
-          }
+          for (t = s; *t; ++t)
+            if (term_7to8bit(t)) {
+              *t = term_7to8bit(t);
+              STRCPY(t + 1, t + 2);
+            }
+          term_strings[p->bt_entry] = s;
+          set_term_option_alloced(&term_strings[p->bt_entry]);
         } else
           term_strings[p->bt_entry] = (char_u *)p->bt_string;
       }
@@ -2970,8 +2968,6 @@ void add_termcode(char_u *name, char_u *string, int flags)
   }
 
   s = vim_strsave(string);
-  if (s == NULL)
-    return;
 
   /* Change leading <Esc>[ to CSI, change <Esc>O to <M-O>. */
   if (flags != 0 && flags != ATC_FROM_TERM && term_7to8bit(string) != 0) {
@@ -4313,8 +4309,8 @@ replace_termcodes (
    * Copy the new string to allocated memory.
    * If this fails, just return from.
    */
-  if ((*bufp = vim_strsave(result)) != NULL)
-    from = *bufp;
+  *bufp = vim_strsave(result);
+  from = *bufp;
   free(result);
   return from;
 }
diff --git a/src/nvim/undo.c b/src/nvim/undo.c
index 4d499cc28e..65ecebf65e 100644
--- a/src/nvim/undo.c
+++ b/src/nvim/undo.c
@@ -700,8 +700,6 @@ char_u *u_get_undo_file_name(char_u *buf_ffname, int reading)
       /* Use same directory as the ffname,
        * "dir/name" -> "dir/.name.un~" */
       undo_file_name = vim_strnsave(ffname, (int)(STRLEN(ffname) + 5));
-      if (undo_file_name == NULL)
-        break;
       p = path_tail(undo_file_name);
       memmove(p + 1, p, STRLEN(p) + 1);
       *p = '.';
@@ -711,8 +709,6 @@ char_u *u_get_undo_file_name(char_u *buf_ffname, int reading)
       if (os_isdir(dir_name)) {
         if (munged_name == NULL) {
           munged_name = vim_strsave(ffname);
-          if (munged_name == NULL)
-            return NULL;
           for (p = munged_name; *p != NUL; mb_ptr_adv(p))
             if (vim_ispathsep(*p))
               *p = '%';