vim-patch:9.0.1221: code is indented more than necessary (#21891)

Problem:    Code is indented more than necessary.
Solution:   Use an early return where it makes sense. (Yegappan Lakshmanan,
            closes vim/vim#11833)

https://github.com/vim/vim/commit/f97a295ccaa9803367f3714cdefce4e2283c771d

Co-authored-by: Yegappan Lakshmanan <yegappan@yahoo.com>

6 files changed, 301 insertions, 263 deletions

diff --git a/src/nvim/ops.c b/src/nvim/ops.c
index c87aa596c3..e08cd082d9 100644
--- a/src/nvim/ops.c
+++ b/src/nvim/ops.c
@@ -1193,18 +1193,20 @@ static void put_reedit_in_typebuf(int silent)
 {
   char_u buf[3];
 
-  if (restart_edit != NUL) {
-    if (restart_edit == 'V') {
-      buf[0] = 'g';
-      buf[1] = 'R';
-      buf[2] = NUL;
-    } else {
-      buf[0] = (char_u)(restart_edit == 'I' ? 'i' : restart_edit);
-      buf[1] = NUL;
-    }
-    if (ins_typebuf((char *)buf, REMAP_NONE, 0, true, silent) == OK) {
-      restart_edit = NUL;
-    }
+  if (restart_edit == NUL) {
+    return;
+  }
+
+  if (restart_edit == 'V') {
+    buf[0] = 'g';
+    buf[1] = 'R';
+    buf[2] = NUL;
+  } else {
+    buf[0] = (char_u)(restart_edit == 'I' ? 'i' : restart_edit);
+    buf[1] = NUL;
+  }
+  if (ins_typebuf((char *)buf, REMAP_NONE, 0, true, silent) == OK) {
+    restart_edit = NUL;
   }
 }
 
@@ -2574,12 +2576,14 @@ void free_register(yankreg_T *reg)
   FUNC_ATTR_NONNULL_ALL
 {
   set_yreg_additional_data(reg, NULL);
-  if (reg->y_array != NULL) {
-    for (size_t i = reg->y_size; i-- > 0;) {  // from y_size - 1 to 0 included
-      xfree(reg->y_array[i]);
-    }
-    XFREE_CLEAR(reg->y_array);
+  if (reg->y_array == NULL) {
+    return;
+  }
+
+  for (size_t i = reg->y_size; i-- > 0;) {  // from y_size - 1 to 0 included
+    xfree(reg->y_array[i]);
   }
+  XFREE_CLEAR(reg->y_array);
 }
 
 /// Yanks the text between "oap->start" and "oap->end" into a yank register.
diff --git a/src/nvim/profile.c b/src/nvim/profile.c
index 8402817710..fd024f2d38 100644
--- a/src/nvim/profile.c
+++ b/src/nvim/profile.c
@@ -703,17 +703,17 @@ void script_prof_save(proftime_T *tm)
 /// Count time spent in children after invoking another script or function.
 void script_prof_restore(const proftime_T *tm)
 {
-  scriptitem_T *si;
+  if (!SCRIPT_ID_VALID(current_sctx.sc_sid)) {
+    return;
+  }
 
-  if (current_sctx.sc_sid > 0 && current_sctx.sc_sid <= script_items.ga_len) {
-    si = &SCRIPT_ITEM(current_sctx.sc_sid);
-    if (si->sn_prof_on && --si->sn_pr_nest == 0) {
-      si->sn_pr_child = profile_end(si->sn_pr_child);
-      // don't count wait time
-      si->sn_pr_child = profile_sub_wait(*tm, si->sn_pr_child);
-      si->sn_pr_children = profile_add(si->sn_pr_children, si->sn_pr_child);
-      si->sn_prl_children = profile_add(si->sn_prl_children, si->sn_pr_child);
-    }
+  scriptitem_T *si = &SCRIPT_ITEM(current_sctx.sc_sid);
+  if (si->sn_prof_on && --si->sn_pr_nest == 0) {
+    si->sn_pr_child = profile_end(si->sn_pr_child);
+    // don't count wait time
+    si->sn_pr_child = profile_sub_wait(*tm, si->sn_pr_child);
+    si->sn_pr_children = profile_add(si->sn_pr_children, si->sn_pr_child);
+    si->sn_prl_children = profile_add(si->sn_prl_children, si->sn_pr_child);
   }
 }
 
@@ -787,17 +787,17 @@ static void script_dump_profile(FILE *fd)
 /// Dump the profiling info.
 void profile_dump(void)
 {
-  FILE *fd;
+  if (profile_fname == NULL) {
+    return;
+  }
 
-  if (profile_fname != NULL) {
-    fd = os_fopen(profile_fname, "w");
-    if (fd == NULL) {
-      semsg(_(e_notopen), profile_fname);
-    } else {
-      script_dump_profile(fd);
-      func_dump_profile(fd);
-      fclose(fd);
-    }
+  FILE *fd = os_fopen(profile_fname, "w");
+  if (fd == NULL) {
+    semsg(_(e_notopen), profile_fname);
+  } else {
+    script_dump_profile(fd);
+    func_dump_profile(fd);
+    fclose(fd);
   }
 }
 
diff --git a/src/nvim/quickfix.c b/src/nvim/quickfix.c
index f0c1011844..58a7379b63 100644
--- a/src/nvim/quickfix.c
+++ b/src/nvim/quickfix.c
@@ -1190,13 +1190,15 @@ static void qf_store_title(qf_list_T *qfl, const char *title)
 {
   XFREE_CLEAR(qfl->qf_title);
 
-  if (title != NULL) {
-    size_t len = strlen(title) + 1;
-    char *p = xmallocz(len);
-
-    qfl->qf_title = p;
-    xstrlcpy(p, title, len + 1);
+  if (title == NULL) {
+    return;
   }
+
+  size_t len = strlen(title) + 1;
+  char *p = xmallocz(len);
+
+  qfl->qf_title = p;
+  xstrlcpy(p, title, len + 1);
 }
 
 /// The title of a quickfix/location list is set, by default, to the command
@@ -1684,14 +1686,16 @@ int qf_stack_get_bufnr(void)
 static void wipe_qf_buffer(qf_info_T *qi)
   FUNC_ATTR_NONNULL_ALL
 {
-  if (qi->qf_bufnr != INVALID_QFBUFNR) {
-    buf_T *const qfbuf = buflist_findnr(qi->qf_bufnr);
-    if (qfbuf != NULL && qfbuf->b_nwindows == 0) {
-      // If the quickfix buffer is not loaded in any window, then
-      // wipe the buffer.
-      close_buffer(NULL, qfbuf, DOBUF_WIPE, false, false);
-      qi->qf_bufnr = INVALID_QFBUFNR;
-    }
+  if (qi->qf_bufnr == INVALID_QFBUFNR) {
+    return;
+  }
+
+  buf_T *const qfbuf = buflist_findnr(qi->qf_bufnr);
+  if (qfbuf != NULL && qfbuf->b_nwindows == 0) {
+    // If the quickfix buffer is not loaded in any window, then
+    // wipe the buffer.
+    close_buffer(NULL, qfbuf, DOBUF_WIPE, false, false);
+    qi->qf_bufnr = INVALID_QFBUFNR;
   }
 }
 
@@ -3878,59 +3882,61 @@ static void qf_update_buffer(qf_info_T *qi, qfline_T *old_last)
 {
   // Check if a buffer for the quickfix list exists.  Update it.
   buf_T *buf = qf_find_buf(qi);
-  if (buf != NULL) {
-    linenr_T old_line_count = buf->b_ml.ml_line_count;
-    int qf_winid = 0;
-
-    win_T *win;
-    if (IS_LL_STACK(qi)) {
-      if (curwin->w_llist == qi) {
-        win = curwin;
-      } else {
-        // Find the file window (non-quickfix) with this location list
-        win = qf_find_win_with_loclist(qi);
-        if (win == NULL) {
-          // File window is not found. Find the location list window.
-          win = qf_find_win(qi);
-        }
-        if (win == NULL) {
-          return;
-        }
+  if (buf == NULL) {
+    return;
+  }
+
+  linenr_T old_line_count = buf->b_ml.ml_line_count;
+  int qf_winid = 0;
+
+  win_T *win;
+  if (IS_LL_STACK(qi)) {
+    if (curwin->w_llist == qi) {
+      win = curwin;
+    } else {
+      // Find the file window (non-quickfix) with this location list
+      win = qf_find_win_with_loclist(qi);
+      if (win == NULL) {
+        // File window is not found. Find the location list window.
+        win = qf_find_win(qi);
+      }
+      if (win == NULL) {
+        return;
       }
-      qf_winid = (int)win->handle;
     }
+    qf_winid = (int)win->handle;
+  }
 
-    // autocommands may cause trouble
-    incr_quickfix_busy();
-
-    aco_save_T aco;
+  // autocommands may cause trouble
+  incr_quickfix_busy();
 
-    if (old_last == NULL) {
-      // set curwin/curbuf to buf and save a few things
-      aucmd_prepbuf(&aco, buf);
-    }
+  aco_save_T aco;
 
-    qf_update_win_titlevar(qi);
+  if (old_last == NULL) {
+    // set curwin/curbuf to buf and save a few things
+    aucmd_prepbuf(&aco, buf);
+  }
 
-    qf_fill_buffer(qf_get_curlist(qi), buf, old_last, qf_winid);
-    buf_inc_changedtick(buf);
+  qf_update_win_titlevar(qi);
 
-    if (old_last == NULL) {
-      (void)qf_win_pos_update(qi, 0);
+  qf_fill_buffer(qf_get_curlist(qi), buf, old_last, qf_winid);
+  buf_inc_changedtick(buf);
 
-      // restore curwin/curbuf and a few other things
-      aucmd_restbuf(&aco);
-    }
+  if (old_last == NULL) {
+    (void)qf_win_pos_update(qi, 0);
 
-    // Only redraw when added lines are visible.  This avoids flickering when
-    // the added lines are not visible.
-    if ((win = qf_find_win(qi)) != NULL && old_line_count < win->w_botline) {
-      redraw_buf_later(buf, UPD_NOT_VALID);
-    }
+    // restore curwin/curbuf and a few other things
+    aucmd_restbuf(&aco);
+  }
 
-    // always called after incr_quickfix_busy()
-    decr_quickfix_busy();
+  // Only redraw when added lines are visible.  This avoids flickering when
+  // the added lines are not visible.
+  if ((win = qf_find_win(qi)) != NULL && old_line_count < win->w_botline) {
+    redraw_buf_later(buf, UPD_NOT_VALID);
   }
+
+  // always called after incr_quickfix_busy()
+  decr_quickfix_busy();
 }
 
 // Add an error line to the quickfix buffer.
@@ -4188,14 +4194,16 @@ static int qf_id2nr(const qf_info_T *const qi, const unsigned qfid)
 static int qf_restore_list(qf_info_T *qi, unsigned save_qfid)
   FUNC_ATTR_NONNULL_ALL FUNC_ATTR_WARN_UNUSED_RESULT
 {
-  if (qf_get_curlist(qi)->qf_id != save_qfid) {
-    const int curlist = qf_id2nr(qi, save_qfid);
-    if (curlist < 0) {
-      // list is not present
-      return FAIL;
-    }
-    qi->qf_curlist = curlist;
+  if (qf_get_curlist(qi)->qf_id == save_qfid) {
+    return OK;
+  }
+
+  const int curlist = qf_id2nr(qi, save_qfid);
+  if (curlist < 0) {
+    // list is not present
+    return FAIL;
   }
+  qi->qf_curlist = curlist;
   return OK;
 }
 
@@ -5736,12 +5744,14 @@ static void wipe_dummy_buffer(buf_T *buf, char *dirname_start)
 // 'autochdir' option have changed it.
 static void unload_dummy_buffer(buf_T *buf, char *dirname_start)
 {
-  if (curbuf != buf) {          // safety check
-    close_buffer(NULL, buf, DOBUF_UNLOAD, false, true);
-
-    // When autocommands/'autochdir' option changed directory: go back.
-    restore_start_dir(dirname_start);
+  if (curbuf == buf) {          // safety check
+    return;
   }
+
+  close_buffer(NULL, buf, DOBUF_UNLOAD, false, true);
+
+  // When autocommands/'autochdir' option changed directory: go back.
+  restore_start_dir(dirname_start);
 }
 
 /// Copy the specified quickfix entry items into a new dict and append the dict
@@ -5866,32 +5876,34 @@ static int qf_get_list_from_lines(dict_T *what, dictitem_T *di, dict_T *retdict)
   int status = FAIL;
 
   // Only a List value is supported
-  if (di->di_tv.v_type == VAR_LIST && di->di_tv.vval.v_list != NULL) {
-    char *errorformat = p_efm;
-    dictitem_T *efm_di;
-    // If errorformat is supplied then use it, otherwise use the 'efm'
-    // option setting
-    if ((efm_di = tv_dict_find(what, S_LEN("efm"))) != NULL) {
-      if (efm_di->di_tv.v_type != VAR_STRING
-          || efm_di->di_tv.vval.v_string == NULL) {
-        return FAIL;
-      }
-      errorformat = efm_di->di_tv.vval.v_string;
-    }
-
-    list_T *l = tv_list_alloc(kListLenMayKnow);
-    qf_info_T *const qi = qf_alloc_stack(QFLT_INTERNAL);
+  if (di->di_tv.v_type != VAR_LIST || di->di_tv.vval.v_list == NULL) {
+    return FAIL;
+  }
 
-    if (qf_init_ext(qi, 0, NULL, NULL, &di->di_tv, errorformat,
-                    true, (linenr_T)0, (linenr_T)0, NULL, NULL) > 0) {
-      (void)get_errorlist(qi, NULL, 0, 0, l);
-      qf_free(&qi->qf_lists[0]);
+  char *errorformat = p_efm;
+  dictitem_T *efm_di;
+  // If errorformat is supplied then use it, otherwise use the 'efm'
+  // option setting
+  if ((efm_di = tv_dict_find(what, S_LEN("efm"))) != NULL) {
+    if (efm_di->di_tv.v_type != VAR_STRING
+        || efm_di->di_tv.vval.v_string == NULL) {
+      return FAIL;
     }
-    xfree(qi);
+    errorformat = efm_di->di_tv.vval.v_string;
+  }
 
-    tv_dict_add_list(retdict, S_LEN("items"), l);
-    status = OK;
+  list_T *l = tv_list_alloc(kListLenMayKnow);
+  qf_info_T *const qi = qf_alloc_stack(QFLT_INTERNAL);
+
+  if (qf_init_ext(qi, 0, NULL, NULL, &di->di_tv, errorformat,
+                  true, (linenr_T)0, (linenr_T)0, NULL, NULL) > 0) {
+    (void)get_errorlist(qi, NULL, 0, 0, l);
+    qf_free(&qi->qf_lists[0]);
   }
+  xfree(qi);
+
+  tv_dict_add_list(retdict, S_LEN("items"), l);
+  status = OK;
 
   return status;
 }
@@ -6934,43 +6946,45 @@ void ex_cexpr(exarg_T *eap)
   // Evaluate the expression.  When the result is a string or a list we can
   // use it to fill the errorlist.
   typval_T tv;
-  if (eval0(eap->arg, &tv, &eap->nextcmd, true) != FAIL) {
-    if ((tv.v_type == VAR_STRING && tv.vval.v_string != NULL)
-        || tv.v_type == VAR_LIST) {
-      incr_quickfix_busy();
-      int res = qf_init_ext(qi, qi->qf_curlist, NULL, NULL, &tv, p_efm,
-                            (eap->cmdidx != CMD_caddexpr
-                             && eap->cmdidx != CMD_laddexpr),
-                            (linenr_T)0, (linenr_T)0,
-                            qf_cmdtitle(*eap->cmdlinep), NULL);
-      if (qf_stack_empty(qi)) {
-        decr_quickfix_busy();
-        goto cleanup;
-      }
-      if (res >= 0) {
-        qf_list_changed(qf_get_curlist(qi));
-      }
-      // Remember the current quickfix list identifier, so that we can
-      // check for autocommands changing the current quickfix list.
-      unsigned save_qfid = qf_get_curlist(qi)->qf_id;
-      if (au_name != NULL) {
-        apply_autocmds(EVENT_QUICKFIXCMDPOST, au_name, curbuf->b_fname, true, curbuf);
-      }
-      // Jump to the first error for a new list and if autocmds didn't
-      // free the list.
-      if (res > 0
-          && (eap->cmdidx == CMD_cexpr || eap->cmdidx == CMD_lexpr)
-          && qflist_valid(wp, save_qfid)) {
-        // display the first error
-        qf_jump_first(qi, save_qfid, eap->forceit);
-      }
+  if (eval0(eap->arg, &tv, &eap->nextcmd, true) == FAIL) {
+    return;
+  }
+
+  if ((tv.v_type == VAR_STRING && tv.vval.v_string != NULL)
+      || tv.v_type == VAR_LIST) {
+    incr_quickfix_busy();
+    int res = qf_init_ext(qi, qi->qf_curlist, NULL, NULL, &tv, p_efm,
+                          (eap->cmdidx != CMD_caddexpr
+                           && eap->cmdidx != CMD_laddexpr),
+                          (linenr_T)0, (linenr_T)0,
+                          qf_cmdtitle(*eap->cmdlinep), NULL);
+    if (qf_stack_empty(qi)) {
       decr_quickfix_busy();
-    } else {
-      emsg(_("E777: String or List expected"));
+      goto cleanup;
     }
-cleanup:
-    tv_clear(&tv);
+    if (res >= 0) {
+      qf_list_changed(qf_get_curlist(qi));
+    }
+    // Remember the current quickfix list identifier, so that we can
+    // check for autocommands changing the current quickfix list.
+    unsigned save_qfid = qf_get_curlist(qi)->qf_id;
+    if (au_name != NULL) {
+      apply_autocmds(EVENT_QUICKFIXCMDPOST, au_name, curbuf->b_fname, true, curbuf);
+    }
+    // Jump to the first error for a new list and if autocmds didn't
+    // free the list.
+    if (res > 0
+        && (eap->cmdidx == CMD_cexpr || eap->cmdidx == CMD_lexpr)
+        && qflist_valid(wp, save_qfid)) {
+      // display the first error
+      qf_jump_first(qi, save_qfid, eap->forceit);
+    }
+    decr_quickfix_busy();
+  } else {
+    emsg(_("E777: String or List expected"));
   }
+cleanup:
+  tv_clear(&tv);
 }
 
 // Get the location list for ":lhelpgrep"
diff --git a/src/nvim/regexp.c b/src/nvim/regexp.c
index ab8e974b29..c2a7dd1011 100644
--- a/src/nvim/regexp.c
+++ b/src/nvim/regexp.c
@@ -1184,32 +1184,36 @@ static int prog_magic_wrong(void)
 // used (to increase speed).
 static void cleanup_subexpr(void)
 {
-  if (rex.need_clear_subexpr) {
-    if (REG_MULTI) {
-      // Use 0xff to set lnum to -1
-      memset(rex.reg_startpos, 0xff, sizeof(lpos_T) * NSUBEXP);
-      memset(rex.reg_endpos, 0xff, sizeof(lpos_T) * NSUBEXP);
-    } else {
-      memset(rex.reg_startp, 0, sizeof(char *) * NSUBEXP);
-      memset(rex.reg_endp, 0, sizeof(char *) * NSUBEXP);
-    }
-    rex.need_clear_subexpr = false;
+  if (!rex.need_clear_subexpr) {
+    return;
+  }
+
+  if (REG_MULTI) {
+    // Use 0xff to set lnum to -1
+    memset(rex.reg_startpos, 0xff, sizeof(lpos_T) * NSUBEXP);
+    memset(rex.reg_endpos, 0xff, sizeof(lpos_T) * NSUBEXP);
+  } else {
+    memset(rex.reg_startp, 0, sizeof(char *) * NSUBEXP);
+    memset(rex.reg_endp, 0, sizeof(char *) * NSUBEXP);
   }
+  rex.need_clear_subexpr = false;
 }
 
 static void cleanup_zsubexpr(void)
 {
-  if (rex.need_clear_zsubexpr) {
-    if (REG_MULTI) {
-      // Use 0xff to set lnum to -1
-      memset(reg_startzpos, 0xff, sizeof(lpos_T) * NSUBEXP);
-      memset(reg_endzpos, 0xff, sizeof(lpos_T) * NSUBEXP);
-    } else {
-      memset(reg_startzp, 0, sizeof(char *) * NSUBEXP);
-      memset(reg_endzp, 0, sizeof(char *) * NSUBEXP);
-    }
-    rex.need_clear_zsubexpr = false;
+  if (!rex.need_clear_zsubexpr) {
+    return;
+  }
+
+  if (REG_MULTI) {
+    // Use 0xff to set lnum to -1
+    memset(reg_startzpos, 0xff, sizeof(lpos_T) * NSUBEXP);
+    memset(reg_endzpos, 0xff, sizeof(lpos_T) * NSUBEXP);
+  } else {
+    memset(reg_startzp, 0, sizeof(char *) * NSUBEXP);
+    memset(reg_endzp, 0, sizeof(char *) * NSUBEXP);
   }
+  rex.need_clear_zsubexpr = false;
 }
 
 // Advance rex.lnum, rex.line and rex.input to the next line.
diff --git a/src/nvim/regexp_bt.c b/src/nvim/regexp_bt.c
index 611d24c091..d8471a7b12 100644
--- a/src/nvim/regexp_bt.c
+++ b/src/nvim/regexp_bt.c
@@ -3468,15 +3468,17 @@ static void save_subexpr(regbehind_T *bp)
   // When "rex.need_clear_subexpr" is set we don't need to save the values, only
   // remember that this flag needs to be set again when restoring.
   bp->save_need_clear_subexpr = rex.need_clear_subexpr;
-  if (!rex.need_clear_subexpr) {
-    for (int i = 0; i < NSUBEXP; i++) {
-      if (REG_MULTI) {
-        bp->save_start[i].se_u.pos = rex.reg_startpos[i];
-        bp->save_end[i].se_u.pos = rex.reg_endpos[i];
-      } else {
-        bp->save_start[i].se_u.ptr = rex.reg_startp[i];
-        bp->save_end[i].se_u.ptr = rex.reg_endp[i];
-      }
+  if (rex.need_clear_subexpr) {
+    return;
+  }
+
+  for (int i = 0; i < NSUBEXP; i++) {
+    if (REG_MULTI) {
+      bp->save_start[i].se_u.pos = rex.reg_startpos[i];
+      bp->save_end[i].se_u.pos = rex.reg_endpos[i];
+    } else {
+      bp->save_start[i].se_u.ptr = rex.reg_startp[i];
+      bp->save_end[i].se_u.ptr = rex.reg_endp[i];
     }
   }
 }
@@ -3487,15 +3489,17 @@ static void restore_subexpr(regbehind_T *bp)
 {
   // Only need to restore saved values when they are not to be cleared.
   rex.need_clear_subexpr = bp->save_need_clear_subexpr;
-  if (!rex.need_clear_subexpr) {
-    for (int i = 0; i < NSUBEXP; i++) {
-      if (REG_MULTI) {
-        rex.reg_startpos[i] = bp->save_start[i].se_u.pos;
-        rex.reg_endpos[i] = bp->save_end[i].se_u.pos;
-      } else {
-        rex.reg_startp[i] = bp->save_start[i].se_u.ptr;
-        rex.reg_endp[i] = bp->save_end[i].se_u.ptr;
-      }
+  if (rex.need_clear_subexpr) {
+    return;
+  }
+
+  for (int i = 0; i < NSUBEXP; i++) {
+    if (REG_MULTI) {
+      rex.reg_startpos[i] = bp->save_start[i].se_u.pos;
+      rex.reg_endpos[i] = bp->save_end[i].se_u.pos;
+    } else {
+      rex.reg_startp[i] = bp->save_start[i].se_u.ptr;
+      rex.reg_endp[i] = bp->save_end[i].se_u.ptr;
     }
   }
 }
diff --git a/src/nvim/regexp_nfa.c b/src/nvim/regexp_nfa.c
index aaa8073240..83a74b6091 100644
--- a/src/nvim/regexp_nfa.c
+++ b/src/nvim/regexp_nfa.c
@@ -3285,25 +3285,27 @@ static void nfa_postfix_dump(char_u *expr, int retval)
   FILE *f;
 
   f = fopen(NFA_REGEXP_DUMP_LOG, "a");
-  if (f != NULL) {
-    fprintf(f, "\n-------------------------\n");
-    if (retval == FAIL) {
-      fprintf(f, ">>> NFA engine failed... \n");
-    } else if (retval == OK) {
-      fprintf(f, ">>> NFA engine succeeded !\n");
-    }
-    fprintf(f, "Regexp: \"%s\"\nPostfix notation (char): \"", expr);
-    for (p = post_start; *p && p < post_ptr; p++) {
-      nfa_set_code(*p);
-      fprintf(f, "%s, ", code);
-    }
-    fprintf(f, "\"\nPostfix notation (int): ");
-    for (p = post_start; *p && p < post_ptr; p++) {
-      fprintf(f, "%d ", *p);
-    }
-    fprintf(f, "\n\n");
-    fclose(f);
+  if (f == NULL) {
+    return;
   }
+
+  fprintf(f, "\n-------------------------\n");
+  if (retval == FAIL) {
+    fprintf(f, ">>> NFA engine failed... \n");
+  } else if (retval == OK) {
+    fprintf(f, ">>> NFA engine succeeded !\n");
+  }
+  fprintf(f, "Regexp: \"%s\"\nPostfix notation (char): \"", expr);
+  for (p = post_start; *p && p < post_ptr; p++) {
+    nfa_set_code(*p);
+    fprintf(f, "%s, ", code);
+  }
+  fprintf(f, "\"\nPostfix notation (int): ");
+  for (p = post_start; *p && p < post_ptr; p++) {
+    fprintf(f, "%d ", *p);
+  }
+  fprintf(f, "\n\n");
+  fclose(f);
 }
 
 // Print the NFA starting with a root node "state".
@@ -3381,22 +3383,24 @@ static void nfa_dump(nfa_regprog_T *prog)
 {
   FILE *debugf = fopen(NFA_REGEXP_DUMP_LOG, "a");
 
-  if (debugf != NULL) {
-    nfa_print_state(debugf, prog->start);
+  if (debugf == NULL) {
+    return;
+  }
 
-    if (prog->reganch) {
-      fprintf(debugf, "reganch: %d\n", prog->reganch);
-    }
-    if (prog->regstart != NUL) {
-      fprintf(debugf, "regstart: %c (decimal: %d)\n",
-              prog->regstart, prog->regstart);
-    }
-    if (prog->match_text != NULL) {
-      fprintf(debugf, "match_text: \"%s\"\n", prog->match_text);
-    }
+  nfa_print_state(debugf, prog->start);
 
-    fclose(debugf);
+  if (prog->reganch) {
+    fprintf(debugf, "reganch: %d\n", prog->reganch);
+  }
+  if (prog->regstart != NUL) {
+    fprintf(debugf, "regstart: %c (decimal: %d)\n",
+            prog->regstart, prog->regstart);
   }
+  if (prog->match_text != NULL) {
+    fprintf(debugf, "match_text: \"%s\"\n", prog->match_text);
+  }
+
+  fclose(debugf);
 }
 #endif  // REGEXP_DEBUG
 
@@ -4427,16 +4431,18 @@ static void clear_sub(regsub_T *sub)
 static void copy_sub(regsub_T *to, regsub_T *from)
 {
   to->in_use = from->in_use;
-  if (from->in_use > 0) {
-    // Copy the match start and end positions.
-    if (REG_MULTI) {
-      memmove(&to->list.multi[0], &from->list.multi[0],
-              sizeof(struct multipos) * (size_t)from->in_use);
-      to->orig_start_col = from->orig_start_col;
-    } else {
-      memmove(&to->list.line[0], &from->list.line[0],
-              sizeof(struct linepos) * (size_t)from->in_use);
-    }
+  if (from->in_use <= 0) {
+    return;
+  }
+
+  // Copy the match start and end positions.
+  if (REG_MULTI) {
+    memmove(&to->list.multi[0], &from->list.multi[0],
+            sizeof(struct multipos) * (size_t)from->in_use);
+    to->orig_start_col = from->orig_start_col;
+  } else {
+    memmove(&to->list.line[0], &from->list.line[0],
+            sizeof(struct linepos) * (size_t)from->in_use);
   }
 }
 
@@ -4446,31 +4452,35 @@ static void copy_sub_off(regsub_T *to, regsub_T *from)
   if (to->in_use < from->in_use) {
     to->in_use = from->in_use;
   }
-  if (from->in_use > 1) {
-    // Copy the match start and end positions.
-    if (REG_MULTI) {
-      memmove(&to->list.multi[1], &from->list.multi[1],
-              sizeof(struct multipos) * (size_t)(from->in_use - 1));
-    } else {
-      memmove(&to->list.line[1], &from->list.line[1],
-              sizeof(struct linepos) * (size_t)(from->in_use - 1));
-    }
+  if (from->in_use <= 1) {
+    return;
+  }
+
+  // Copy the match start and end positions.
+  if (REG_MULTI) {
+    memmove(&to->list.multi[1], &from->list.multi[1],
+            sizeof(struct multipos) * (size_t)(from->in_use - 1));
+  } else {
+    memmove(&to->list.line[1], &from->list.line[1],
+            sizeof(struct linepos) * (size_t)(from->in_use - 1));
   }
 }
 
 // Like copy_sub() but only do the end of the main match if \ze is present.
 static void copy_ze_off(regsub_T *to, regsub_T *from)
 {
-  if (rex.nfa_has_zend) {
-    if (REG_MULTI) {
-      if (from->list.multi[0].end_lnum >= 0) {
-        to->list.multi[0].end_lnum = from->list.multi[0].end_lnum;
-        to->list.multi[0].end_col = from->list.multi[0].end_col;
-      }
-    } else {
-      if (from->list.line[0].end != NULL) {
-        to->list.line[0].end = from->list.line[0].end;
-      }
+  if (!rex.nfa_has_zend) {
+    return;
+  }
+
+  if (REG_MULTI) {
+    if (from->list.multi[0].end_lnum >= 0) {
+      to->list.multi[0].end_lnum = from->list.multi[0].end_lnum;
+      to->list.multi[0].end_col = from->list.multi[0].end_col;
+    }
+  } else {
+    if (from->list.line[0].end != NULL) {
+      to->list.line[0].end = from->list.line[0].end;
     }
   }
 }
@@ -7554,11 +7564,13 @@ fail:
 // Free a compiled regexp program, returned by nfa_regcomp().
 static void nfa_regfree(regprog_T *prog)
 {
-  if (prog != NULL) {
-    xfree(((nfa_regprog_T *)prog)->match_text);
-    xfree(((nfa_regprog_T *)prog)->pattern);
-    xfree(prog);
+  if (prog == NULL) {
+    return;
   }
+
+  xfree(((nfa_regprog_T *)prog)->match_text);
+  xfree(((nfa_regprog_T *)prog)->pattern);
+  xfree(prog);
 }
 
 /// Match a regexp against a string.