patch 9.0.0342: ":wincmd =" equalizes in two directions

Problem:    ":wincmd =" equalizes in two directions.
Solution:   Make ":vertical wincmd =" equalize vertically only and
            ":horizontal wincmd =" equalize horizontally only.

runtime/doc/windows.txt

@@ -256,9 +256,16 @@ and 'winminwidth' are relevant.
 						*:vert* *:vertical*
 :vert[ical] {cmd}
 		Execute {cmd}.  If it contains a command that splits a window,
-		it will be split vertically.
+		it will be split vertically.  For `vertical wincmd =` windows
+		will be equialized only vertically.
 		Doesn't work for |:execute| and |:normal|.
 
+						*:hor* *:horizontal*
+:hor[izontal] {cmd}
+		Execute {cmd}.  Currently only makes a difference for
+		`horizontal wincmd =`, which will equal windows only
+		horizontally.
+
 :lefta[bove] {cmd}				*:lefta* *:leftabove*
 :abo[veleft] {cmd}				*:abo* *:aboveleft*
 		Execute {cmd}.  If it contains a command that splits a window,
@@ -553,6 +560,10 @@ CTRL-W =	Make all windows (almost) equally high and wide, but use
 		'winheight' and 'winwidth' for the current window.
 		Windows with 'winfixheight' set keep their height and windows
 		with 'winfixwidth' set keep their width.
+		To equalize only vertically (make window equally high) use
+		`vertical wincmd =`
+		To equalize only horizontally (make window equally wide) use
+		`horizontal wincmd =`
 
 :res[ize] -N					*:res* *:resize* *CTRL-W_-*
 CTRL-W -	Decrease current window height by N (default 1).

src/ex_cmdidxs.h

@@ -13,24 +13,24 @@ static const unsigned short cmdidxs1[26] =
   /* f */ 166,
   /* g */ 183,
   /* h */ 189,
-  /* i */ 198,
+  /* i */ 199,
-  /* j */ 218,
+  /* j */ 219,
-  /* k */ 220,
+  /* k */ 221,
-  /* l */ 225,
+  /* l */ 226,
-  /* m */ 288,
+  /* m */ 289,
-  /* n */ 306,
+  /* n */ 307,
-  /* o */ 326,
+  /* o */ 327,
-  /* p */ 338,
+  /* p */ 339,
-  /* q */ 377,
+  /* q */ 378,
-  /* r */ 380,
+  /* r */ 381,
-  /* s */ 400,
+  /* s */ 401,
-  /* t */ 470,
+  /* t */ 471,
-  /* u */ 516,
+  /* u */ 517,
-  /* v */ 527,
+  /* v */ 528,
-  /* w */ 548,
+  /* w */ 549,
-  /* x */ 562,
+  /* x */ 563,
-  /* y */ 572,
+  /* y */ 573,
-  /* z */ 573
+  /* z */ 574
 };
 
 /*
@@ -48,7 +48,7 @@ static const unsigned char cmdidxs2[26][26] =
   /* e */ {  1,  0,  2,  0,  0,  0,  0,  0,  0,  0,  0,  9, 11, 12,  0,  0,  0,  0,  0,  0,  0, 23,  0, 24,  0,  0 },
   /* f */ {  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0, 10,  0,  0,  0,  0,  0, 16,  0,  0,  0,  0,  0 },
   /* g */ {  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  1,  0,  0,  2,  0,  0,  4,  5,  0,  0,  0,  0 },
-  /* h */ {  5,  0,  0,  0,  0,  0,  0,  0,  6,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0 },
+  /* h */ {  5,  0,  0,  0,  0,  0,  0,  0,  6,  0,  0,  0,  0,  0,  9,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0 },
   /* i */ {  1,  0,  0,  0,  0,  3,  0,  0,  0,  4,  0,  5,  6,  0,  0,  0,  0,  0, 15,  0, 17,  0,  0,  0,  0,  0 },
   /* j */ {  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  1,  0,  0,  0,  0,  0 },
   /* k */ {  0,  0,  0,  0,  1,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0 },
@@ -69,4 +69,4 @@ static const unsigned char cmdidxs2[26][26] =
   /* z */ {  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0 }
 };
 
-static const int command_count = 590;
+static const int command_count = 591;

src/ex_cmds.h

@@ -707,6 +707,9 @@ EXCMD(CMD_hide,		"hide",		ex_hide,
 EXCMD(CMD_history,	"history",	ex_history,
 	EX_EXTRA|EX_TRLBAR|EX_CMDWIN|EX_LOCK_OK,
 	ADDR_NONE),
+EXCMD(CMD_horizontal,	"horizontal",	ex_wrongmodifier,
+	EX_NEEDARG|EX_EXTRA|EX_NOTRLCOM,
+	ADDR_NONE),
 EXCMD(CMD_insert,	"insert",	ex_append,
 	EX_BANG|EX_RANGE|EX_TRLBAR|EX_CMDWIN|EX_LOCK_OK|EX_MODIFY,
 	ADDR_LINES),

src/ex_docmd.c

@@ -2987,8 +2987,13 @@ parse_command_modifiers(
 			    continue;
 			}
 
+	    case 'h':	if (checkforcmd_noparen(&eap->cmd, "horizontal", 3))
+			{
+			    cmod->cmod_split |= WSP_HOR;
+			    continue;
+			}
 			// ":hide" and ":hide | cmd" are not modifiers
-	    case 'h':	if (p != eap->cmd || !checkforcmd_noparen(&p, "hide", 3)
+			if (p != eap->cmd || !checkforcmd_noparen(&p, "hide", 3)
 					       || *p == NUL || ends_excmd(*p))
 			    break;
 			eap->cmd = p;

src/testdir/test_window_cmd.vim

@@ -367,6 +367,46 @@ func Test_window_height()
   bw Xa Xb Xc
 endfunc
 
+func Test_wincmd_equal()
+  edit Xone
+  below split Xtwo
+  rightbelow vsplit Xthree
+  call assert_equal('Xone', bufname(winbufnr(1)))
+  call assert_equal('Xtwo', bufname(winbufnr(2)))
+  call assert_equal('Xthree', bufname(winbufnr(3)))
+
+  " Xone and Xtwo should be about the same height
+  let [wh1, wh2] = [winheight(1), winheight(2)]
+  call assert_inrange(wh1 - 1, wh1 + 1, wh2)
+  " Xtwo and Xthree should be about the same width
+  let [ww2, ww3] = [winwidth(2), winwidth(3)]
+  call assert_inrange(ww2 - 1, ww2 + 1, ww3)
+
+  1wincmd w
+  10wincmd _
+  2wincmd w
+  20wincmd |
+  call assert_equal(10, winheight(1))
+  call assert_equal(20, winwidth(2))
+
+  " equalizing horizontally doesn't change the heights
+  hor wincmd =
+  call assert_equal(10, winheight(1))
+  let [ww2, ww3] = [winwidth(2), winwidth(3)]
+  call assert_inrange(ww2 - 1, ww2 + 1, ww3)
+
+  2wincmd w
+  20wincmd |
+  call assert_equal(20, winwidth(2))
+  " equalizing vertically doesn't change the widths
+  vert wincmd =
+  call assert_equal(20, winwidth(2))
+  let [wh1, wh2] = [winheight(1), winheight(2)]
+  call assert_inrange(wh1 - 1, wh1 + 1, wh2)
+
+  bwipe Xone Xtwo Xthree
+endfunc
+
 func Test_window_width()
   e Xa
   vsplit Xb

src/version.c

@@ -707,6 +707,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    342,
 /**/
     341,
 /**/

src/vim.h

@@ -1209,14 +1209,15 @@ extern int (*dyn_libintl_wputenv)(const wchar_t *envstring);
 /*
  * arguments for win_split()
  */
-#define WSP_ROOM	1	// require enough room
+#define WSP_ROOM	0x01	// require enough room
-#define WSP_VERT	2	// split vertically
+#define WSP_VERT	0x02	// split/equalize vertically
-#define WSP_TOP		4	// window at top-left of shell
+#define WSP_HOR		0x04	// equalize horizontally
-#define WSP_BOT		8	// window at bottom-right of shell
+#define WSP_TOP		0x08	// window at top-left of shell
-#define WSP_HELP	16	// creating the help window
+#define WSP_BOT		0x10	// window at bottom-right of shell
-#define WSP_BELOW	32	// put new window below/right
+#define WSP_HELP	0x20	// creating the help window
-#define WSP_ABOVE	64	// put new window above/left
+#define WSP_BELOW	0x40	// put new window below/right
-#define WSP_NEWLOC	128	// don't copy location list
+#define WSP_ABOVE	0x80	// put new window above/left
+#define WSP_NEWLOC	0x100	// don't copy location list
 
 /*
  * arguments for gui_set_shellsize()

src/window.c

@@ -434,12 +434,16 @@ newwindow:
 			| ((nchar == 'H' || nchar == 'K') ? WSP_TOP : WSP_BOT));
 		break;
 
-// make all windows the same height
+// make all windows the same width and/or height
     case '=':
+		{
+		    int mod = cmdmod.cmod_split & (WSP_VERT | WSP_HOR);
 #ifdef FEAT_GUI
 		    need_mouse_correct = TRUE;
 #endif
-		win_equal(NULL, FALSE, 'b');
+		    win_equal(NULL, FALSE,
+			   mod == WSP_VERT ? 'v' : mod == WSP_HOR ? 'h' : 'b');
+		}
 		break;
 
 // increase current window height