patch 7.4.1394

Problem:    Can't sort inside a sort function.
Solution:   Use a struct to store the sort parameters. (Jacob Niehus)

Author: brammool

src/eval.c

@@ -18790,16 +18790,21 @@ typedef struct
     int		idx;
 } sortItem_T;
 
-static int	item_compare_ic;
-static int	item_compare_numeric;
-static int	item_compare_numbers;
+/* struct storing information about current sort */
+typedef struct
+{
+    int		item_compare_ic;
+    int		item_compare_numeric;
+    int		item_compare_numbers;
 #ifdef FEAT_FLOAT
-static int	item_compare_float;
-#endif
-static char_u	*item_compare_func;
-static dict_T	*item_compare_selfdict;
-static int	item_compare_func_err;
-static int	item_compare_keep_zero;
+    int		item_compare_float;
+#endif
+    char_u	*item_compare_func;
+    dict_T	*item_compare_selfdict;
+    int		item_compare_func_err;
+    int		item_compare_keep_zero;
+} sortinfo_T;
+static sortinfo_T	*sortinfo = NULL;
 static void	do_sort_uniq(typval_T *argvars, typval_T *rettv, int sort);
 #define ITEM_COMPARE_FAIL 999
 
@@ -18825,7 +18830,7 @@ item_compare(const void *s1, const void *s2)
     tv1 = &si1->item->li_tv;
     tv2 = &si2->item->li_tv;
 
-    if (item_compare_numbers)
+    if (sortinfo->item_compare_numbers)
     {
 	long	v1 = get_tv_number(tv1);
 	long	v2 = get_tv_number(tv2);
@@ -18834,7 +18839,7 @@ item_compare(const void *s1, const void *s2)
     }
 
 #ifdef FEAT_FLOAT
-    if (item_compare_float)
+    if (sortinfo->item_compare_float)
     {
 	float_T	v1 = get_tv_float(tv1);
 	float_T	v2 = get_tv_float(tv2);
@@ -18848,7 +18853,7 @@ item_compare(const void *s1, const void *s2)
      * non-string to do what the docs promise. */
     if (tv1->v_type == VAR_STRING)
     {
-	if (tv2->v_type != VAR_STRING || item_compare_numeric)
+	if (tv2->v_type != VAR_STRING || sortinfo->item_compare_numeric)
 	    p1 = (char_u *)"'";
 	else
 	    p1 = tv1->vval.v_string;
@@ -18857,7 +18862,7 @@ item_compare(const void *s1, const void *s2)
 	p1 = tv2string(tv1, &tofree1, numbuf1, 0);
     if (tv2->v_type == VAR_STRING)
     {
-	if (tv1->v_type != VAR_STRING || item_compare_numeric)
+	if (tv1->v_type != VAR_STRING || sortinfo->item_compare_numeric)
 	    p2 = (char_u *)"'";
 	else
 	    p2 = tv2->vval.v_string;
@@ -18868,9 +18873,9 @@ item_compare(const void *s1, const void *s2)
 	p1 = (char_u *)"";
     if (p2 == NULL)
 	p2 = (char_u *)"";
-    if (!item_compare_numeric)
+    if (!sortinfo->item_compare_numeric)
     {
-	if (item_compare_ic)
+	if (sortinfo->item_compare_ic)
 	    res = STRICMP(p1, p2);
 	else
 	    res = STRCMP(p1, p2);
@@ -18885,7 +18890,7 @@ item_compare(const void *s1, const void *s2)
 
     /* When the result would be zero, compare the item indexes.  Makes the
      * sort stable. */
-    if (res == 0 && !item_compare_keep_zero)
+    if (res == 0 && !sortinfo->item_compare_keep_zero)
 	res = si1->idx > si2->idx ? 1 : -1;
 
     vim_free(tofree1);
@@ -18906,7 +18911,7 @@ item_compare2(const void *s1, const void *s2)
     int		dummy;
 
     /* shortcut after failure in previous call; compare all items equal */
-    if (item_compare_func_err)
+    if (sortinfo->item_compare_func_err)
 	return 0;
 
     si1 = (sortItem_T *)s1;
@@ -18918,23 +18923,24 @@ item_compare2(const void *s1, const void *s2)
     copy_tv(&si2->item->li_tv, &argv[1]);
 
     rettv.v_type = VAR_UNKNOWN;		/* clear_tv() uses this */
-    res = call_func(item_compare_func, (int)STRLEN(item_compare_func),
+    res = call_func(sortinfo->item_compare_func,
+		 		 (int)STRLEN(sortinfo->item_compare_func),
 				 &rettv, 2, argv, 0L, 0L, &dummy, TRUE,
-				 item_compare_selfdict);
+				 sortinfo->item_compare_selfdict);
     clear_tv(&argv[0]);
     clear_tv(&argv[1]);
 
     if (res == FAIL)
 	res = ITEM_COMPARE_FAIL;
     else
-	res = get_tv_number_chk(&rettv, &item_compare_func_err);
-    if (item_compare_func_err)
+	res = get_tv_number_chk(&rettv, &sortinfo->item_compare_func_err);
+    if (sortinfo->item_compare_func_err)
 	res = ITEM_COMPARE_FAIL;  /* return value has wrong type */
     clear_tv(&rettv);
 
     /* When the result would be zero, compare the pointers themselves.  Makes
      * the sort stable. */
-    if (res == 0 && !item_compare_keep_zero)
+    if (res == 0 && !sortinfo->item_compare_keep_zero)
 	res = si1->idx > si2->idx ? 1 : -1;
 
     return res;
@@ -18949,9 +18955,16 @@ do_sort_uniq(typval_T *argvars, typval_T *rettv, int sort)
     list_T	*l;
     listitem_T	*li;
     sortItem_T	*ptrs;
+    sortinfo_T	*old_sortinfo;
+    sortinfo_T	info;
     long	len;
     long	i;
 
+    /* Pointer to current info struct used in compare function. Save and
+     * restore the current one for nested calls. */
+    old_sortinfo = sortinfo;
+    sortinfo = &info;
+
     if (argvars[0].v_type != VAR_LIST)
 	EMSG2(_(e_listarg), sort ? "sort()" : "uniq()");
     else
@@ -18960,62 +18973,62 @@ do_sort_uniq(typval_T *argvars, typval_T *rettv, int sort)
 	if (l == NULL || tv_check_lock(l->lv_lock,
 	     (char_u *)(sort ? N_("sort() argument") : N_("uniq() argument")),
 									TRUE))
-	    return;
+	    goto theend;
 	rettv->vval.v_list = l;
 	rettv->v_type = VAR_LIST;
 	++l->lv_refcount;
 
 	len = list_len(l);
 	if (len <= 1)
-	    return;	/* short list sorts pretty quickly */
+	    goto theend;	/* short list sorts pretty quickly */
 
-	item_compare_ic = FALSE;
-	item_compare_numeric = FALSE;
-	item_compare_numbers = FALSE;
+	info.item_compare_ic = FALSE;
+	info.item_compare_numeric = FALSE;
+	info.item_compare_numbers = FALSE;
 #ifdef FEAT_FLOAT
-	item_compare_float = FALSE;
+	info.item_compare_float = FALSE;
 #endif
-	item_compare_func = NULL;
-	item_compare_selfdict = NULL;
+	info.item_compare_func = NULL;
+	info.item_compare_selfdict = NULL;
 	if (argvars[1].v_type != VAR_UNKNOWN)
 	{
 	    /* optional second argument: {func} */
 	    if (argvars[1].v_type == VAR_FUNC)
-		item_compare_func = argvars[1].vval.v_string;
+		info.item_compare_func = argvars[1].vval.v_string;
 	    else
 	    {
 		int	    error = FALSE;
 
 		i = get_tv_number_chk(&argvars[1], &error);
 		if (error)
-		    return;		/* type error; errmsg already given */
+		    goto theend;	/* type error; errmsg already given */
 		if (i == 1)
-		    item_compare_ic = TRUE;
+		    info.item_compare_ic = TRUE;
 		else
-		    item_compare_func = get_tv_string(&argvars[1]);
-		if (item_compare_func != NULL)
+		    info.item_compare_func = get_tv_string(&argvars[1]);
+		if (info.item_compare_func != NULL)
 		{
-		    if (STRCMP(item_compare_func, "n") == 0)
+		    if (STRCMP(info.item_compare_func, "n") == 0)
 		    {
-			item_compare_func = NULL;
-			item_compare_numeric = TRUE;
+			info.item_compare_func = NULL;
+			info.item_compare_numeric = TRUE;
 		    }
-		    else if (STRCMP(item_compare_func, "N") == 0)
+		    else if (STRCMP(info.item_compare_func, "N") == 0)
 		    {
-			item_compare_func = NULL;
-			item_compare_numbers = TRUE;
+			info.item_compare_func = NULL;
+			info.item_compare_numbers = TRUE;
 		    }
 #ifdef FEAT_FLOAT
-		    else if (STRCMP(item_compare_func, "f") == 0)
+		    else if (STRCMP(info.item_compare_func, "f") == 0)
 		    {
-			item_compare_func = NULL;
-			item_compare_float = TRUE;
+			info.item_compare_func = NULL;
+			info.item_compare_float = TRUE;
 		    }
 #endif
-		    else if (STRCMP(item_compare_func, "i") == 0)
+		    else if (STRCMP(info.item_compare_func, "i") == 0)
 		    {
-			item_compare_func = NULL;
-			item_compare_ic = TRUE;
+			info.item_compare_func = NULL;
+			info.item_compare_ic = TRUE;
 		    }
 		}
 	    }
@@ -19026,16 +19039,16 @@ do_sort_uniq(typval_T *argvars, typval_T *rettv, int sort)
 		if (argvars[2].v_type != VAR_DICT)
 		{
 		    EMSG(_(e_dictreq));
-		    return;
+		    goto theend;
 		}
-		item_compare_selfdict = argvars[2].vval.v_dict;
+		info.item_compare_selfdict = argvars[2].vval.v_dict;
 	    }
 	}
 
 	/* Make an array with each entry pointing to an item in the List. */
 	ptrs = (sortItem_T *)alloc((int)(len * sizeof(sortItem_T)));
 	if (ptrs == NULL)
-	    return;
+	    goto theend;
 
 	i = 0;
 	if (sort)
@@ -19048,20 +19061,21 @@ do_sort_uniq(typval_T *argvars, typval_T *rettv, int sort)
 		++i;
 	    }
 
-	    item_compare_func_err = FALSE;
-	    item_compare_keep_zero = FALSE;
+	    info.item_compare_func_err = FALSE;
+	    info.item_compare_keep_zero = FALSE;
 	    /* test the compare function */
-	    if (item_compare_func != NULL
+	    if (info.item_compare_func != NULL
 		    && item_compare2((void *)&ptrs[0], (void *)&ptrs[1])
 							 == ITEM_COMPARE_FAIL)
 		EMSG(_("E702: Sort compare function failed"));
 	    else
 	    {
 		/* Sort the array with item pointers. */
 		qsort((void *)ptrs, (size_t)len, sizeof(sortItem_T),
-		    item_compare_func == NULL ? item_compare : item_compare2);
+		    info.item_compare_func == NULL
+					       ? item_compare : item_compare2);
 
-		if (!item_compare_func_err)
+		if (!info.item_compare_func_err)
 		{
 		    /* Clear the List and append the items in sorted order. */
 		    l->lv_first = l->lv_last = l->lv_idx_item = NULL;
@@ -19076,9 +19090,9 @@ do_sort_uniq(typval_T *argvars, typval_T *rettv, int sort)
 	    int	(*item_compare_func_ptr)(const void *, const void *);
 
 	    /* f_uniq(): ptrs will be a stack of items to remove */
-	    item_compare_func_err = FALSE;
-	    item_compare_keep_zero = TRUE;
-	    item_compare_func_ptr = item_compare_func
+	    info.item_compare_func_err = FALSE;
+	    info.item_compare_keep_zero = TRUE;
+	    item_compare_func_ptr = info.item_compare_func
 					       ? item_compare2 : item_compare;
 
 	    for (li = l->lv_first; li != NULL && li->li_next != NULL;
@@ -19087,14 +19101,14 @@ do_sort_uniq(typval_T *argvars, typval_T *rettv, int sort)
 		if (item_compare_func_ptr((void *)&li, (void *)&li->li_next)
 									 == 0)
 		    ptrs[i++].item = li;
-		if (item_compare_func_err)
+		if (info.item_compare_func_err)
 		{
 		    EMSG(_("E882: Uniq compare function failed"));
 		    break;
 		}
 	    }
 
-	    if (!item_compare_func_err)
+	    if (!info.item_compare_func_err)
 	    {
 		while (--i >= 0)
 		{
@@ -19113,6 +19127,8 @@ do_sort_uniq(typval_T *argvars, typval_T *rettv, int sort)
 
 	vim_free(ptrs);
     }
+theend:
+    sortinfo = old_sortinfo;
 }
 
 /*

src/testdir/test_sort.vim

@@ -1,5 +1,14 @@
 " Test sort()
 
+:func Compare1(a, b) abort
+    call sort(range(3), 'Compare2')
+    return a:a ># a:b
+:endfunc
+
+:func Compare2(a, b) abort
+    return a:a <# a:b
+:endfunc
+
 func Test_sort_strings()
   " numbers compared as strings
   call assert_equal([1, 2, 3], sort([3, 2, 1]))
@@ -21,3 +30,8 @@ endfunc
 func Test_sort_float()
   call assert_equal([0.28, 3, 13.5], sort([13.5, 0.28, 3], 'f'))
 endfunc
+
+func Test_sort_nested()
+  " test ability to call sort() from a compare function
+  call assert_equal([1, 3, 5], sort([3, 1, 5], 'Compare1'))
+endfunc

src/version.c

@@ -748,6 +748,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1394,
 /**/
     1393,
 /**/