patch 9.0.1166: code is indented more than necessaryv9.0.1166

Problem:    Code is indented more than necessary.
Solution:   Use an early return where it makes sense. (Yegappan Lakshmanan,
            closes #11792)

22 files changed, 907 insertions, 881 deletions

diff --git a/src/autocmd.c b/src/autocmd.c
index 20c5afa744..c18d2a15ab 100644
--- a/src/autocmd.c
+++ b/src/autocmd.c
@@ -1063,18 +1063,18 @@ au_get_grouparg(char_u **argp)
 
     for (p = arg; *p && !VIM_ISWHITE(*p) && *p != '|'; ++p)
 	;
-    if (p > arg)
-    {
-	group_name = vim_strnsave(arg, 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
-	else
-	    *argp = skipwhite(p);	// match, skip over group name
-	vim_free(group_name);
-    }
+    if (p <= arg)
+	return AUGROUP_ALL;
+
+    group_name = vim_strnsave(arg, 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
+    else
+	*argp = skipwhite(p);	// match, skip over group name
+    vim_free(group_name);
     return group;
 }
 
diff --git a/src/buffer.c b/src/buffer.c
index 4016822616..a3de68df29 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -357,34 +357,34 @@ open_buffer(
     apply_autocmds(EVENT_BUFENTER, NULL, NULL, FALSE, curbuf);
 #endif
 
-    if (retval == OK)
+    if (retval != OK)
+	return retval;
+
+    // The autocommands may have changed the current buffer.  Apply the
+    // modelines to the correct buffer, if it still exists and is loaded.
+    if (bufref_valid(&old_curbuf) && old_curbuf.br_buf->b_ml.ml_mfp != NULL)
     {
-	// The autocommands may have changed the current buffer.  Apply the
-	// modelines to the correct buffer, if it still exists and is loaded.
-	if (bufref_valid(&old_curbuf) && old_curbuf.br_buf->b_ml.ml_mfp != NULL)
-	{
-	    aco_save_T	aco;
+	aco_save_T	aco;
 
-	    // Go to the buffer that was opened, make sure it is in a window.
-	    // If not then skip it.
-	    aucmd_prepbuf(&aco, old_curbuf.br_buf);
-	    if (curbuf == old_curbuf.br_buf)
-	    {
-		do_modelines(0);
-		curbuf->b_flags &= ~(BF_CHECK_RO | BF_NEVERLOADED);
+	// Go to the buffer that was opened, make sure it is in a window.
+	// If not then skip it.
+	aucmd_prepbuf(&aco, old_curbuf.br_buf);
+	if (curbuf == old_curbuf.br_buf)
+	{
+	    do_modelines(0);
+	    curbuf->b_flags &= ~(BF_CHECK_RO | BF_NEVERLOADED);
 
-		if ((flags & READ_NOWINENTER) == 0)
+	    if ((flags & READ_NOWINENTER) == 0)
 #ifdef FEAT_EVAL
-		    apply_autocmds_retval(EVENT_BUFWINENTER, NULL, NULL,
-						       FALSE, curbuf, &retval);
+		apply_autocmds_retval(EVENT_BUFWINENTER, NULL, NULL,
+			FALSE, curbuf, &retval);
 #else
-		    apply_autocmds(EVENT_BUFWINENTER, NULL, NULL,
-								FALSE, curbuf);
+	    apply_autocmds(EVENT_BUFWINENTER, NULL, NULL,
+		    FALSE, curbuf);
 #endif
 
-		// restore curwin/curbuf and a few other things
-		aucmd_restbuf(&aco);
-	    }
+	    // restore curwin/curbuf and a few other things
+	    aucmd_restbuf(&aco);
 	}
     }
 
@@ -1761,7 +1761,6 @@ do_bufdel(
 	}
     }
 
-
     return errormsg;
 }
 
@@ -3019,20 +3018,20 @@ fname_match(
     char_u	*p;
 
     // extra check for valid arguments
-    if (name != NULL && rmp->regprog != NULL)
+    if (name == NULL || rmp->regprog == NULL)
+	return NULL;
+
+    // Ignore case when 'fileignorecase' or the argument is set.
+    rmp->rm_ic = p_fic || ignore_case;
+    if (vim_regexec(rmp, name, (colnr_T)0))
+	match = name;
+    else if (rmp->regprog != NULL)
     {
-	// Ignore case when 'fileignorecase' or the argument is set.
-	rmp->rm_ic = p_fic || ignore_case;
-	if (vim_regexec(rmp, name, (colnr_T)0))
+	// Replace $(HOME) with '~' and try matching again.
+	p = home_replace_save(NULL, name);
+	if (p != NULL && vim_regexec(rmp, p, (colnr_T)0))
 	    match = name;
-	else if (rmp->regprog != NULL)
-	{
-	    // Replace $(HOME) with '~' and try matching again.
-	    p = home_replace_save(NULL, name);
-	    if (p != NULL && vim_regexec(rmp, p, (colnr_T)0))
-		match = name;
-	    vim_free(p);
-	}
+	vim_free(p);
     }
 
     return match;
@@ -3160,16 +3159,15 @@ wininfo_other_tab_diff(wininfo_T *wip)
 {
     win_T	*wp;
 
-    if (wip->wi_opt.wo_diff)
-    {
-	FOR_ALL_WINDOWS(wp)
-	    // return FALSE when it's a window in the current tab page, thus
-	    // the buffer was in diff mode here
-	    if (wip->wi_win == wp)
-		return FALSE;
-	return TRUE;
-    }
-    return FALSE;
+    if (!wip->wi_opt.wo_diff)
+	return FALSE;
+
+    FOR_ALL_WINDOWS(wp)
+	// return FALSE when it's a window in the current tab page, thus
+	// the buffer was in diff mode here
+	if (wip->wi_win == wp)
+	    return FALSE;
+    return TRUE;
 }
 #endif
 
@@ -3198,27 +3196,27 @@ find_wininfo(
 		&& (!need_options || wip->wi_optset))
 	    break;
 
+    if (wip != NULL)
+	return wip;
+
     // If no wininfo for curwin, use the first in the list (that doesn't have
     // 'diff' set and is in another tab page).
     // If "need_options" is TRUE skip entries that don't have options set,
     // unless the window is editing "buf", so we can copy from the window
     // itself.
-    if (wip == NULL)
-    {
 #ifdef FEAT_DIFF
-	if (skip_diff_buffer)
-	{
-	    FOR_ALL_BUF_WININFO(buf, wip)
-		if (!wininfo_other_tab_diff(wip)
-			&& (!need_options || wip->wi_optset
-			    || (wip->wi_win != NULL
-					     && wip->wi_win->w_buffer == buf)))
-		    break;
-	}
-	else
-#endif
-	    wip = buf->b_wininfo;
+    if (skip_diff_buffer)
+    {
+	FOR_ALL_BUF_WININFO(buf, wip)
+	    if (!wininfo_other_tab_diff(wip)
+		    && (!need_options || wip->wi_optset
+			|| (wip->wi_win != NULL
+			    && wip->wi_win->w_buffer == buf)))
+		break;
     }
+    else
+#endif
+	wip = buf->b_wininfo;
     return wip;
 }
 
diff --git a/src/charset.c b/src/charset.c
index 8d7b61a4a6..0bad471e45 100644
--- a/src/charset.c
+++ b/src/charset.c
@@ -345,24 +345,25 @@ transstr(char_u *s)
     }
     else
 	res = alloc(vim_strsize(s) + 1);
-    if (res != NULL)
+
+    if (res == NULL)
+	return NULL;
+
+    *res = NUL;
+    p = s;
+    while (*p != NUL)
     {
-	*res = NUL;
-	p = s;
-	while (*p != NUL)
+	if (has_mbyte && (l = (*mb_ptr2len)(p)) > 1)
 	{
-	    if (has_mbyte && (l = (*mb_ptr2len)(p)) > 1)
-	    {
-		c = (*mb_ptr2char)(p);
-		if (vim_isprintc(c))
-		    STRNCAT(res, p, l);	// append printable multi-byte char
-		else
-		    transchar_hex(res + STRLEN(res), c);
-		p += l;
-	    }
+	    c = (*mb_ptr2char)(p);
+	    if (vim_isprintc(c))
+		STRNCAT(res, p, l);	// append printable multi-byte char
 	    else
-		STRCAT(res, transchar_byte(*p++));
+		transchar_hex(res + STRLEN(res), c);
+	    p += l;
 	}
+	else
+	    STRCAT(res, transchar_byte(*p++));
     }
     return res;
 }
diff --git a/src/cindent.c b/src/cindent.c
index 105e08cc8c..bc71cc092f 100644
--- a/src/cindent.c
+++ b/src/cindent.c
@@ -46,21 +46,21 @@ cin_is_cinword(char_u *line)
 
     cinw_len = (int)STRLEN(curbuf->b_p_cinw) + 1;
     cinw_buf = alloc(cinw_len);
-    if (cinw_buf != NULL)
+    if (cinw_buf == NULL)
+	return FALSE;
+
+    line = skipwhite(line);
+    for (cinw = curbuf->b_p_cinw; *cinw; )
     {
-	line = skipwhite(line);
-	for (cinw = curbuf->b_p_cinw; *cinw; )
+	len = copy_option_part(&cinw, cinw_buf, cinw_len, ",");
+	if (STRNCMP(line, cinw_buf, len) == 0
+		&& (!vim_iswordc(line[len]) || !vim_iswordc(line[len - 1])))
 	{
-	    len = copy_option_part(&cinw, cinw_buf, cinw_len, ",");
-	    if (STRNCMP(line, cinw_buf, len) == 0
-		    && (!vim_iswordc(line[len]) || !vim_iswordc(line[len - 1])))
-	    {
-		retval = TRUE;
-		break;
-	    }
+	    retval = TRUE;
+	    break;
 	}
-	vim_free(cinw_buf);
     }
+    vim_free(cinw_buf);
     return retval;
 }
 
@@ -644,43 +644,42 @@ cin_islabel(void)		// XXX
     if (cin_isscopedecl(s))
 	return FALSE;
 
-    if (cin_islabel_skip(&s))
-    {
-	// Only accept a label if the previous line is terminated or is a case
-	// label.
-	pos_T	cursor_save;
-	pos_T	*trypos;
-	char_u	*line;
+    if (!cin_islabel_skip(&s))
+	return FALSE;
 
-	cursor_save = curwin->w_cursor;
-	while (curwin->w_cursor.lnum > 1)
-	{
-	    --curwin->w_cursor.lnum;
+    // Only accept a label if the previous line is terminated or is a case
+    // label.
+    pos_T	cursor_save;
+    pos_T	*trypos;
+    char_u	*line;
 
-	    // If we're in a comment or raw string now, skip to the start of
-	    // it.
-	    curwin->w_cursor.col = 0;
-	    if ((trypos = ind_find_start_CORS(NULL)) != NULL) // XXX
-		curwin->w_cursor = *trypos;
+    cursor_save = curwin->w_cursor;
+    while (curwin->w_cursor.lnum > 1)
+    {
+	--curwin->w_cursor.lnum;
 
-	    line = ml_get_curline();
-	    if (cin_ispreproc(line))	// ignore #defines, #if, etc.
-		continue;
-	    if (*(line = cin_skipcomment(line)) == NUL)
-		continue;
+	// If we're in a comment or raw string now, skip to the start of
+	// it.
+	curwin->w_cursor.col = 0;
+	if ((trypos = ind_find_start_CORS(NULL)) != NULL) // XXX
+	    curwin->w_cursor = *trypos;
+
+	line = ml_get_curline();
+	if (cin_ispreproc(line))	// ignore #defines, #if, etc.
+	    continue;
+	if (*(line = cin_skipcomment(line)) == NUL)
+	    continue;
 
-	    curwin->w_cursor = cursor_save;
-	    if (cin_isterminated(line, TRUE, FALSE)
-		    || cin_isscopedecl(line)
-		    || cin_iscase(line, TRUE)
-		    || (cin_islabel_skip(&line) && cin_nocode(line)))
-		return TRUE;
-	    return FALSE;
-	}
 	curwin->w_cursor = cursor_save;
-	return TRUE;		// label at start of file???
+	if (cin_isterminated(line, TRUE, FALSE)
+		|| cin_isscopedecl(line)
+		|| cin_iscase(line, TRUE)
+		|| (cin_islabel_skip(&line) && cin_nocode(line)))
+	    return TRUE;
+	return FALSE;
     }
-    return FALSE;
+    curwin->w_cursor = cursor_save;
+    return TRUE;		// label at start of file???
 }
 
 /*
@@ -1688,18 +1687,18 @@ find_match_paren_after_brace (int ind_maxparen)	    // XXX
 {
     pos_T	*trypos = find_match_paren(ind_maxparen);
 
-    if (trypos != NULL)
-    {
-	pos_T	*tryposBrace = find_start_brace();
-
-	// If both an unmatched '(' and '{' is found.  Ignore the '('
-	// position if the '{' is further down.
-	if (tryposBrace != NULL
-		&& (trypos->lnum != tryposBrace->lnum
-		    ? trypos->lnum < tryposBrace->lnum
-		    : trypos->col < tryposBrace->col))
-	    trypos = NULL;
-    }
+    if (trypos == NULL)
+	return NULL;
+
+    pos_T	*tryposBrace = find_start_brace();
+
+    // If both an unmatched '(' and '{' is found.  Ignore the '('
+    // position if the '{' is further down.
+    if (tryposBrace != NULL
+	    && (trypos->lnum != tryposBrace->lnum
+		? trypos->lnum < tryposBrace->lnum
+		: trypos->col < tryposBrace->col))
+	trypos = NULL;
     return trypos;
 }
 
diff --git a/src/clientserver.c b/src/clientserver.c
index 2a091a6e97..dfbb8a8b03 100644
--- a/src/clientserver.c
+++ b/src/clientserver.c
@@ -157,22 +157,22 @@ serverConvert(
     char_u	*res = data;
 
     *tofree = NULL;
-    if (client_enc != NULL && p_enc != NULL)
-    {
-	vimconv_T	vimconv;
+    if (client_enc == NULL || p_enc == NULL)
+	return res;
 
-	vimconv.vc_type = CONV_NONE;
-	if (convert_setup(&vimconv, client_enc, p_enc) != FAIL
-					      && vimconv.vc_type != CONV_NONE)
-	{
-	    res = string_convert(&vimconv, data, NULL);
-	    if (res == NULL)
-		res = data;
-	    else
-		*tofree = res;
-	}
-	convert_setup(&vimconv, NULL, NULL);
+    vimconv_T	vimconv;
+
+    vimconv.vc_type = CONV_NONE;
+    if (convert_setup(&vimconv, client_enc, p_enc) != FAIL
+	    && vimconv.vc_type != CONV_NONE)
+    {
+	res = string_convert(&vimconv, data, NULL);
+	if (res == NULL)
+	    res = data;
+	else
+	    *tofree = res;
     }
+    convert_setup(&vimconv, NULL, NULL);
     return res;
 }
 #endif
diff --git a/src/cmdexpand.c b/src/cmdexpand.c
index cc34f296a8..5a47f6a24a 100644
--- a/src/cmdexpand.c
+++ b/src/cmdexpand.c
@@ -1850,21 +1850,22 @@ find_cmd_after_substitute_cmd(char_u *arg)
 find_cmd_after_isearch_cmd(expand_T *xp, char_u *arg)
 {
     arg = skipwhite(skipdigits(arg));	    // skip count
-    if (*arg == '/')	// Match regexp, not just whole words
+    if (*arg != '/')
+	return NULL;
+
+    // Match regexp, not just whole words
+    for (++arg; *arg && *arg != '/'; arg++)
+	if (*arg == '\\' && arg[1] != NUL)
+	    arg++;
+    if (*arg)
     {
-	for (++arg; *arg && *arg != '/'; arg++)
-	    if (*arg == '\\' && arg[1] != NUL)
-		arg++;
-	if (*arg)
-	{
-	    arg = skipwhite(arg + 1);
+	arg = skipwhite(arg + 1);
 
-	    // Check for trailing illegal characters
-	    if (*arg == NUL || vim_strchr((char_u *)"|\"\n", *arg) == NULL)
-		xp->xp_context = EXPAND_NOTHING;
-	    else
-		return arg;
-	}
+	// Check for trailing illegal characters
+	if (*arg == NUL || vim_strchr((char_u *)"|\"\n", *arg) == NULL)
+	    xp->xp_context = EXPAND_NOTHING;
+	else
+	    return arg;
     }
 
     return NULL;
@@ -2780,7 +2781,7 @@ get_breakadd_arg(expand_T *xp UNUSED, int idx)
 {
     char *opts[] = {"expr", "file", "func", "here"};
 
-    if (idx >=0 && idx <= 3)
+    if (idx >= 0 && idx <= 3)
     {
 	// breakadd {expr, file, func, here}
 	if (breakpt_expand_what == EXP_BREAKPT_ADD)
diff --git a/src/debugger.c b/src/debugger.c
index 1352f49994..f627a9a4da 100644
--- a/src/debugger.c
+++ b/src/debugger.c
@@ -315,14 +315,14 @@ get_maxbacktrace_level(char_u *sname)
     char	*p, *q;
     int		maxbacktrace = 0;
 
-    if (sname != NULL)
+    if (sname == NULL)
+	return 0;
+
+    p = (char *)sname;
+    while ((q = strstr(p, "..")) != NULL)
     {
-	p = (char *)sname;
-	while ((q = strstr(p, "..")) != NULL)
-	{
-	    p = q + 2;
-	    maxbacktrace++;
-	}
+	p = q + 2;
+	maxbacktrace++;
     }
     return maxbacktrace;
 }
@@ -486,21 +486,20 @@ dbg_check_skipped(exarg_T *eap)
 {
     int		prev_got_int;
 
-    if (debug_skipped)
-    {
-	// Save the value of got_int and reset it.  We don't want a previous
-	// interruption cause flushing the input buffer.
-	prev_got_int = got_int;
-	got_int = FALSE;
-	debug_breakpoint_name = debug_skipped_name;
-	// eap->skip is TRUE
-	eap->skip = FALSE;
-	(void)dbg_check_breakpoint(eap);
-	eap->skip = TRUE;
-	got_int |= prev_got_int;
-	return TRUE;
-    }
-    return FALSE;
+    if (!debug_skipped)
+	return FALSE;
+
+    // Save the value of got_int and reset it.  We don't want a previous
+    // interruption cause flushing the input buffer.
+    prev_got_int = got_int;
+    got_int = FALSE;
+    debug_breakpoint_name = debug_skipped_name;
+    // eap->skip is TRUE
+    eap->skip = FALSE;
+    (void)dbg_check_breakpoint(eap);
+    eap->skip = TRUE;
+    got_int |= prev_got_int;
+    return TRUE;
 }
 
 /*
diff --git a/src/dict.c b/src/dict.c
index d45fcff0ab..6941845cda 100644
--- a/src/dict.c
+++ b/src/dict.c
@@ -30,21 +30,21 @@ dict_alloc(void)
     dict_T *d;
 
     d = ALLOC_CLEAR_ONE(dict_T);
-    if (d != NULL)
-    {
-	// Add the dict to the list of dicts for garbage collection.
-	if (first_dict != NULL)
-	    first_dict->dv_used_prev = d;
-	d->dv_used_next = first_dict;
-	d->dv_used_prev = NULL;
-	first_dict = d;
-
-	hash_init(&d->dv_hashtab);
-	d->dv_lock = 0;
-	d->dv_scope = 0;
-	d->dv_refcount = 0;
-	d->dv_copyID = 0;
-    }
+    if (d == NULL)
+	return NULL;
+
+    // Add the dict to the list of dicts for garbage collection.
+    if (first_dict != NULL)
+	first_dict->dv_used_prev = d;
+    d->dv_used_next = first_dict;
+    d->dv_used_prev = NULL;
+    first_dict = d;
+
+    hash_init(&d->dv_hashtab);
+    d->dv_lock = 0;
+    d->dv_scope = 0;
+    d->dv_refcount = 0;
+    d->dv_copyID = 0;
     return d;
 }
 
@@ -228,13 +228,13 @@ dictitem_alloc(char_u *key)
     size_t len = STRLEN(key);
 
     di = alloc(offsetof(dictitem_T, di_key) + len + 1);
-    if (di != NULL)
-    {
-	mch_memmove(di->di_key, key, len + 1);
-	di->di_flags = DI_FLAGS_ALLOC;
-	di->di_tv.v_lock = 0;
-	di->di_tv.v_type = VAR_UNKNOWN;
-    }
+    if (di == NULL)
+	return NULL;
+
+    mch_memmove(di->di_key, key, len + 1);
+    di->di_flags = DI_FLAGS_ALLOC;
+    di->di_tv.v_lock = 0;
+    di->di_tv.v_type = VAR_UNKNOWN;
     return di;
 }
 
@@ -248,12 +248,12 @@ dictitem_copy(dictitem_T *org)
     size_t	len = STRLEN(org->di_key);
 
     di = alloc(offsetof(dictitem_T, di_key) + len + 1);
-    if (di != NULL)
-    {
-	mch_memmove(di->di_key, org->di_key, len + 1);
-	di->di_flags = DI_FLAGS_ALLOC;
-	copy_tv(&org->di_tv, &di->di_tv);
-    }
+    if (di == NULL)
+	return NULL;
+
+    mch_memmove(di->di_key, org->di_key, len + 1);
+    di->di_flags = DI_FLAGS_ALLOC;
+    copy_tv(&org->di_tv, &di->di_tv);
     return di;
 }
 
@@ -303,53 +303,53 @@ dict_copy(dict_T *orig, int deep, int top, int copyID)
 	return NULL;
 
     copy = dict_alloc();
-    if (copy != NULL)
+    if (copy == NULL)
+	return NULL;
+
+    if (copyID != 0)
     {
-	if (copyID != 0)
-	{
-	    orig->dv_copyID = copyID;
-	    orig->dv_copydict = copy;
-	}
-	if (orig->dv_type == NULL || top || deep)
-	    copy->dv_type = NULL;
-	else
-	    copy->dv_type = alloc_type(orig->dv_type);
+	orig->dv_copyID = copyID;
+	orig->dv_copydict = copy;
+    }
+    if (orig->dv_type == NULL || top || deep)
+	copy->dv_type = NULL;
+    else
+	copy->dv_type = alloc_type(orig->dv_type);
 
-	todo = (int)orig->dv_hashtab.ht_used;
-	for (hi = orig->dv_hashtab.ht_array; todo > 0 && !got_int; ++hi)
+    todo = (int)orig->dv_hashtab.ht_used;
+    for (hi = orig->dv_hashtab.ht_array; todo > 0 && !got_int; ++hi)
+    {
+	if (!HASHITEM_EMPTY(hi))
 	{
-	    if (!HASHITEM_EMPTY(hi))
-	    {
-		--todo;
+	    --todo;
 
-		di = dictitem_alloc(hi->hi_key);
-		if (di == NULL)
-		    break;
-		if (deep)
-		{
-		    if (item_copy(&HI2DI(hi)->di_tv, &di->di_tv,
-						  deep, FALSE, copyID) == FAIL)
-		    {
-			vim_free(di);
-			break;
-		    }
-		}
-		else
-		    copy_tv(&HI2DI(hi)->di_tv, &di->di_tv);
-		if (dict_add(copy, di) == FAIL)
+	    di = dictitem_alloc(hi->hi_key);
+	    if (di == NULL)
+		break;
+	    if (deep)
+	    {
+		if (item_copy(&HI2DI(hi)->di_tv, &di->di_tv,
+			    deep, FALSE, copyID) == FAIL)
 		{
-		    dictitem_free(di);
+		    vim_free(di);
 		    break;
 		}
 	    }
+	    else
+		copy_tv(&HI2DI(hi)->di_tv, &di->di_tv);
+	    if (dict_add(copy, di) == FAIL)
+	    {
+		dictitem_free(di);
+		break;
+	    }
 	}
+    }
 
-	++copy->dv_refcount;
-	if (todo > 0)
-	{
-	    dict_unref(copy);
-	    copy = NULL;
-	}
+    ++copy->dv_refcount;
+    if (todo > 0)
+    {
+	dict_unref(copy);
+	copy = NULL;
     }
 
     return copy;
diff --git a/src/diff.c b/src/diff.c
index 41cfefe5e6..ec8c8f175d 100644
--- a/src/diff.c
+++ b/src/diff.c
@@ -559,14 +559,14 @@ diff_alloc_new(tabpage_T *tp, diff_T *dprev, diff_T *dp)
     diff_T	*dnew;
 
     dnew = ALLOC_ONE(diff_T);
-    if (dnew != NULL)
-    {
-	dnew->df_next = dp;
-	if (dprev == NULL)
-	    tp->tp_first_diff = dnew;
-	else
-	    dprev->df_next = dnew;
-    }
+    if (dnew == NULL)
+	return NULL;
+
+    dnew->df_next = dp;
+    if (dprev == NULL)
+	tp->tp_first_diff = dnew;
+    else
+	dprev->df_next = dnew;
     return dnew;
 }
 
diff --git a/src/digraph.c b/src/digraph.c
index 88643e35f7..97a72e1d55 100644
--- a/src/digraph.c
+++ b/src/digraph.c
@@ -1533,29 +1533,30 @@ get_digraph(
     c = plain_vgetc();
     --no_mapping;
     --allow_keys;
-    if (c != ESC)		// ESC cancels CTRL-K
+
+    if (c == ESC)		// ESC cancels CTRL-K
+	return NUL;
+
+    if (IS_SPECIAL(c))	// insert special key code
+	return c;
+    if (cmdline)
     {
-	if (IS_SPECIAL(c))	// insert special key code
-	    return c;
-	if (cmdline)
-	{
-	    if (char2cells(c) == 1
+	if (char2cells(c) == 1
 #if defined(FEAT_CRYPT) || defined(FEAT_EVAL)
-		    && cmdline_star == 0
+		&& cmdline_star == 0
 #endif
-		    )
-		putcmdline(c, TRUE);
-	}
-	else
-	    add_to_showcmd(c);
-	++no_mapping;
-	++allow_keys;
-	cc = plain_vgetc();
-	--no_mapping;
-	--allow_keys;
-	if (cc != ESC)	    // ESC cancels CTRL-K
-	    return digraph_get(c, cc, TRUE);
+	   )
+	    putcmdline(c, TRUE);
     }
+    else
+	add_to_showcmd(c);
+    ++no_mapping;
+    ++allow_keys;
+    cc = plain_vgetc();
+    --no_mapping;
+    --allow_keys;
+    if (cc != ESC)	    // ESC cancels CTRL-K
+	return digraph_get(c, cc, TRUE);
     return NUL;
 }
 
diff --git a/src/edit.c b/src/edit.c
index 4a89fe13fb..983f1aca6d 100644
--- a/src/edit.c
+++ b/src/edit.c
@@ -2970,12 +2970,12 @@ 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;
-    }
+    if (s == NULL)
+	return NULL;
+
+    len = (int)STRLEN(s);
+    if (len > 0 && s[len - 1] == ESC)	// remove trailing ESC
+	s[len - 1] = NUL;
     return s;
 }
 
diff --git a/src/evalfunc.c b/src/evalfunc.c
index 274d0bdaa5..0184d61778 100644
--- a/src/evalfunc.c
+++ b/src/evalfunc.c
@@ -2950,22 +2950,22 @@ internal_func_check_arg_types(
 {
     argcheck_T	*argchecks = global_functions[idx].f_argcheck;
 
-    if (argchecks != NULL)
-    {
-	argcontext_T context;
+    if (argchecks == NULL)
+	return OK;
 
-	context.arg_count = argcount;
-	context.arg_types = types;
-	context.arg_cctx = cctx;
-	for (int i = 0; i < argcount; ++i)
-	    if (argchecks[i] != NULL)
-	    {
-		context.arg_idx = i;
-		if (argchecks[i](types[i].type_curr, types[i].type_decl,
-							     &context) == FAIL)
-		    return FAIL;
-	    }
-    }
+    argcontext_T context;
+
+    context.arg_count = argcount;
+    context.arg_types = types;
+    context.arg_cctx = cctx;
+    for (int i = 0; i < argcount; ++i)
+	if (argchecks[i] != NULL)
+	{
+	    context.arg_idx = i;
+	    if (argchecks[i](types[i].type_curr, types[i].type_decl,
+			&context) == FAIL)
+		return FAIL;
+	}
     return OK;
 }
 
@@ -3475,14 +3475,14 @@ get_optional_window(typval_T *argvars, int idx)
 {
     win_T   *win = curwin;
 
-    if (argvars[idx].v_type != VAR_UNKNOWN)
+    if (argvars[idx].v_type == VAR_UNKNOWN)
+	return curwin;
+
+    win = find_win_by_nr_or_id(&argvars[idx]);
+    if (win == NULL)
     {
-	win = find_win_by_nr_or_id(&argvars[idx]);
-	if (win == NULL)
-	{
-	    emsg(_(e_invalid_window_number));
-	    return NULL;
-	}
+	emsg(_(e_invalid_window_number));
+	return NULL;
     }
     return win;
 }
@@ -8624,43 +8624,43 @@ get_search_arg(typval_T *varp, int *flagsp)
     char_u	nbuf[NUMBUFLEN];
     int		mask;
 
-    if (varp->v_type != VAR_UNKNOWN)
+    if (varp->v_type == VAR_UNKNOWN)
+	return FORWARD;
+
+    flags = tv_get_string_buf_chk(varp, nbuf);
+    if (flags == NULL)
+	return 0;		// type error; errmsg already given
+    while (*flags != NUL)
     {
-	flags = tv_get_string_buf_chk(varp, nbuf);
-	if (flags == NULL)
-	    return 0;		// type error; errmsg already given
-	while (*flags != NUL)
+	switch (*flags)
 	{
-	    switch (*flags)
-	    {
-		case 'b': dir = BACKWARD; break;
-		case 'w': p_ws = TRUE; break;
-		case 'W': p_ws = FALSE; break;
-		default:  mask = 0;
-			  if (flagsp != NULL)
-			     switch (*flags)
-			     {
-				 case 'c': mask = SP_START; break;
-				 case 'e': mask = SP_END; break;
-				 case 'm': mask = SP_RETCOUNT; break;
-				 case 'n': mask = SP_NOMOVE; break;
-				 case 'p': mask = SP_SUBPAT; break;
-				 case 'r': mask = SP_REPEAT; break;
-				 case 's': mask = SP_SETPCMARK; break;
-				 case 'z': mask = SP_COLUMN; break;
-			     }
-			  if (mask == 0)
+	    case 'b': dir = BACKWARD; break;
+	    case 'w': p_ws = TRUE; break;
+	    case 'W': p_ws = FALSE; break;
+	    default:  mask = 0;
+		      if (flagsp != NULL)
+			  switch (*flags)
 			  {
-			      semsg(_(e_invalid_argument_str), flags);
-			      dir = 0;
+			      case 'c': mask = SP_START; break;
+			      case 'e': mask = SP_END; break;
+			      case 'm': mask = SP_RETCOUNT; break;
+			      case 'n': mask = SP_NOMOVE; break;
+			      case 'p': mask = SP_SUBPAT; break;
+			      case 'r': mask = SP_REPEAT; break;
+			      case 's': mask = SP_SETPCMARK; break;
+			      case 'z': mask = SP_COLUMN; break;
 			  }
-			  else
-			      *flagsp |= mask;
-	    }
-	    if (dir == 0)
-		break;
-	    ++flags;
+		      if (mask == 0)
+		      {
+			  semsg(_(e_invalid_argument_str), flags);
+			  dir = 0;
+		      }
+		      else
+			  *flagsp |= mask;
 	}
+	if (dir == 0)
+	    break;
+	++flags;
     }
     return dir;
 }
diff --git a/src/evalwindow.c b/src/evalwindow.c
index 8b47b98fd1..fde90f2561 100644
--- a/src/evalwindow.c
+++ b/src/evalwindow.c
@@ -24,29 +24,29 @@ win_getid(typval_T *argvars)
     if (argvars[0].v_type == VAR_UNKNOWN)
 	return curwin->w_id;
     winnr = tv_get_number(&argvars[0]);
-    if (winnr > 0)
+    if (winnr <= 0)
+	return 0;
+
+    if (argvars[1].v_type == VAR_UNKNOWN)
+	wp = firstwin;
+    else
     {
-	if (argvars[1].v_type == VAR_UNKNOWN)
+	tabpage_T	*tp;
+	int		tabnr = tv_get_number(&argvars[1]);
+
+	FOR_ALL_TABPAGES(tp)
+	    if (--tabnr == 0)
+		break;
+	if (tp == NULL)
+	    return -1;
+	if (tp == curtab)
 	    wp = firstwin;
 	else
-	{
-	    tabpage_T	*tp;
-	    int		tabnr = tv_get_number(&argvars[1]);
-
-	    FOR_ALL_TABPAGES(tp)
-		if (--tabnr == 0)
-		    break;
-	    if (tp == NULL)
-		return -1;
-	    if (tp == curtab)
-		wp = firstwin;
-	    else
-		wp = tp->tp_firstwin;
-	}
-	for ( ; wp != NULL; wp = wp->w_next)
-	    if (--winnr == 0)
-		return wp->w_id;
+	    wp = tp->tp_firstwin;
     }
+    for ( ; wp != NULL; wp = wp->w_next)
+	if (--winnr == 0)
+	    return wp->w_id;
     return 0;
 }
 
@@ -380,18 +380,20 @@ get_winnr(tabpage_T *tp, typval_T *argvar)
 	}
     }
 
-    if (nr > 0)
-	for (wp = (tp == curtab) ? firstwin : tp->tp_firstwin;
-					      wp != twin; wp = wp->w_next)
+    if (nr <= 0)
+	return 0;
+
+    for (wp = (tp == curtab) ? firstwin : tp->tp_firstwin;
+	    wp != twin; wp = wp->w_next)
+    {
+	if (wp == NULL)
 	{
-	    if (wp == NULL)
-	    {
-		// didn't find it in this tabpage
-		nr = 0;
-		break;
-	    }
-	    ++nr;
+	    // didn't find it in this tabpage
+	    nr = 0;
+	    break;
 	}
+	++nr;
+    }
     return nr;
 }
 
diff --git a/src/ex_cmds.c b/src/ex_cmds.c
index faff4aadaf..32c72879cc 100644
--- a/src/ex_cmds.c
+++ b/src/ex_cmds.c
@@ -5279,67 +5279,67 @@ prepare_tagpreview(