patch 8.0.0262: Farsi support is barely tested

Problem:    Farsi support is barely tested.
Solution:   Add more tests for Farsi.  Clean up the code.

src/edit.c

@@ -6166,6 +6166,9 @@ insertchar(
 		&& (!has_mbyte || MB_BYTE2LEN_CHECK(c) == 1)
 #endif
 		&& i < INPUT_BUFLEN
+# ifdef FEAT_FKMAP
+		&& !(p_fkmap && KeyTyped) /* Farsi mode mapping moves cursor */
+# endif
 		&& (textwidth == 0
 		    || (virtcol += byte2cells(buf[i - 1])) < (colnr_T)textwidth)
 		&& !(!no_abbr && !vim_iswordc(c) && vim_iswordc(buf[i - 1])))
@@ -6174,10 +6177,6 @@ insertchar(
 	    c = vgetc();
 	    if (p_hkmap && KeyTyped)
 		c = hkmap(c);		    /* Hebrew mode mapping */
-# ifdef FEAT_FKMAP
-	    if (p_fkmap && KeyTyped)
-		c = fkmap(c);		    /* Farsi mode mapping */
-# endif
 	    buf[i++] = c;
 #else
 	    buf[i++] = vgetc();

src/farsi.c

@@ -15,26 +15,7 @@
 
 #if defined(FEAT_FKMAP) || defined(PROTO)
 
-static int toF_Xor_X_(int c);
-static int F_is_TyE(int c);
-static int F_is_TyC_TyD(int c);
 static int F_is_TyB_TyC_TyD(int src, int offset);
-static int toF_TyB(int c);
-static void put_curr_and_l_to_X(int c);
-static void put_and_redo(int c);
-static void chg_c_toX_orX(void);
-static void chg_c_to_X_orX_(void);
-static void chg_c_to_X_or_X(void);
-static void chg_l_to_X_orX_(void);
-static void chg_l_toXor_X(void);
-static void chg_r_to_Xor_X_(void);
-static int toF_leading(int c);
-static int toF_Rjoin(int c);
-static int canF_Ljoin(int c);
-static int canF_Rjoin(int c);
-static int F_isterm(int c);
-static int toF_ending(int c);
-static void lrswapbuf(char_u *buf, int len);
 
 /*
  * Convert the given Farsi character into a _X or _X_ type
@@ -275,6 +256,15 @@ toF_TyB(int c)
     return c;
 }
 
+
+    static void
+put_and_redo(int c)
+{
+    pchar_cursor(c);
+    AppendCharToRedobuff(K_BS);
+    AppendCharToRedobuff(c);
+}
+
 /*
  * Overwrite the current redo and cursor characters + left adjust.
  */
@@ -312,14 +302,6 @@ put_curr_and_l_to_X(int c)
     put_and_redo(c);
 }
 
-    static void
-put_and_redo(int c)
-{
-    pchar_cursor(c);
-    AppendCharToRedobuff(K_BS);
-    AppendCharToRedobuff(c);
-}
-
 /*
  * Change the char. under the cursor to a X_ or X type
  */
@@ -447,7 +429,6 @@ chg_c_toX_orX(void)
 /*
  * Change the char. under the cursor to a _X_ or X_ type
  */
-
     static void
 chg_c_to_X_orX_(void)
 {
@@ -598,7 +579,6 @@ chg_l_to_X_orX_(void)
 /*
  * Change the character left to the cursor to a X or _X type
  */
-
     static void
 chg_l_toXor_X(void)
 {
@@ -667,7 +647,6 @@ chg_l_toXor_X (void)
 /*
  * Change the character right to the cursor to a _X or _X_ type
  */
-
     static void
 chg_r_to_Xor_X_(void)
 {
@@ -692,19 +671,22 @@ chg_r_to_Xor_X_(void)
 /*
  * Map Farsi keyboard when in fkmap mode.
  */
-
     int
 fkmap(int c)
 {
     int		tempc;
-    static int	revins;
+    int		insert_mode = (State & INSERT);
+    static int	revins = 0;
 
     if (IS_SPECIAL(c))
 	return c;
 
+    if (insert_mode)
+    {
 	if (VIM_ISDIGIT(c) || ((c == '.' || c == '+' || c == '-' ||
 	    c == '^' || c == '%' || c == '#' || c == '=') && revins))
 	{
+	    /* Numbers are entered left-to-right. */
 	    if (!revins)
 	    {
 		if (curwin->w_cursor.col)
@@ -729,10 +711,9 @@ fkmap(int c)
 	    ++revins;
 	    p_ri = 1;
 	}
-    else
-    {
-	if (revins)
+	else if (revins)
 	{
+	    /* Stop entering number. */
 	    arrow_used = TRUE;
 	    (void)stop_arrow();
 
@@ -844,13 +825,12 @@ fkmap(int c)
 	case  NL:
 	case  TAB:
 
-	    if (p_ri && c == NL && curwin->w_cursor.col)
+	    if (p_ri && c == NL && curwin->w_cursor.col && insert_mode)
 	    {
 		/*
 		 * If the char before the cursor is _X_ or X_ do not change
 		 * the one under the cursor with X type.
 		 */
-
 		dec_cursor();
 
 		if (F_isalpha(gchar_cursor()))
@@ -920,6 +900,9 @@ fkmap(int c)
 		}
 		break;
 	    }
+
+	    if (insert_mode)
+	    {
 		if (!p_ri)
 		    dec_cursor();
 
@@ -1040,6 +1023,7 @@ fkmap(int c)
 
 		if (!p_ri)
 		    inc_cursor();
+	    }
 
 	    tempc = 0;
 
@@ -1376,7 +1360,7 @@ fkmap(int c)
 	    break;
     }
 
-    if ((F_isalpha(tempc) || F_isdigit(tempc)))
+    if (F_isalpha(tempc) || F_isdigit(tempc))
     {
 	if (!curwin->w_cursor.col && STRLEN(ml_get_curline()))
 	{

src/testdir/test_farsi.vim

@@ -1,4 +1,5 @@
 " Simplistic testing of Farsi mode.
+" Note: must be edited with latin1 encoding.
 
 if !has('farsi')
   finish
@@ -82,3 +83,21 @@ func Test_farsi_map()
   set noaltkeymap
   bwipe!
 endfunc
+
+func Test_input_farsi()
+  new
+  setlocal rightleft fkmap
+  " numbers switch input direction
+  call feedkeys("aabc0123456789.+-^%#=xyz\<Esc>", 'tx')
+  call assert_equal("\x8c<38>ν<EFBFBD><CEBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>\x93<39>", getline('.'))
+
+  " all non-number special chars
+  call feedkeys("aB E F H I K L M O P Q R T U W Y ` !  @ # $ % ^ & * () - _ = + \\ | : \" .  / < > ? \<Esc>", 'tx')
+  call assert_equal("\x8c<38>ν<EFBFBD><CEBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>\x93ա<33><D5A1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> [<5B>]<5D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>񠢠<EFBFBD><F1A0A2A0><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>蠨<EFBFBD><E8A0A8><EFBFBD><EFBFBD>頽<EFBFBD><E9A0BD><EFBFBD><EFBFBD><EFBFBD>꠺<EFBFBD><EAA0BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>", getline('.'))
+
+  " all letter chars
+  call feedkeys("aa A b c C d D e f g G h i j J k l m n N o p q r s S t u v V w x X y z Z ; \ , [ ] \<Esc>", 'tx')
+  call assert_equal("\x8c<38>ν<EFBFBD><CEBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>\x93ա<33><D5A1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> [<5B>]<5D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>񠢠<EFBFBD><F1A0A2A0><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>蠨<EFBFBD><E8A0A8><EFBFBD><EFBFBD>頽<EFBFBD><E9A0BD><EFBFBD><EFBFBD><EFBFBD>꠺<EFBFBD><EAA0BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ѡ<EFBFBD><D1A0>̠ΠϠ<CEA0><CFA0><EFBFBD><EFBFBD>Ơàܠ<C3A0><DCA0><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Š<EFBFBD><C5A0>ޠݠĠˠˠʠɠӠ٠Р<D9A0><D0A0>ؠ֠͠͠ҠԠԠנՠ<D7A0><D5A0>ڠ<EFBFBD>ߠǠȠ", getline('.'))
+
+  bwipe!
+endfunc

src/version.c

@@ -764,6 +764,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    262,
 /**/
     261,
 /**/