vim-patch:8.0.1553: find digraph to insert a character #8190

Problem:    Cannot see what digraph is used to insert a character.
Solution:   Show the digraph with the "ga" command. (Christian Brabandt)
https://github.com/vim/vim/commit/5f73ef8d20070cd45c9aea4dc33c2e0657f5515c

close #8190

8 files changed, 131 insertions, 58 deletions

diff --git a/runtime/doc/various.txt b/runtime/doc/various.txt
index 917419e0f5..11ee8f8ca9 100644
--- a/runtime/doc/various.txt
+++ b/runtime/doc/various.txt
@@ -37,23 +37,34 @@ CTRL-L			Clear and redraw the screen.  The redraw may happen
 <
 :as[cii]	or					*ga* *:as* *:ascii*
 ga			Print the ascii value of the character under the
-			cursor in decimal, hexadecimal and octal.  For
-			example, when the cursor is on a 'R':
+			cursor in decimal, hexadecimal and octal.
+			Mnemonic: Get Ascii value.
+			
+			For example, when the cursor is on a 'R':
 				<R>  82,  Hex 52,  Octal 122 ~
 			When the character is a non-standard ASCII character,
 			but printable according to the 'isprint' option, the
-			non-printable version is also given.  When the
-			character is larger than 127, the <M-x> form is also
-			printed.  For example:
+			non-printable version is also given.
+			
+			When the character is larger than 127, the <M-x> form
+			is also printed.  For example:
 				<~A>  <M-^A>  129,  Hex 81,  Octal 201 ~
 				<p>  <|~>  <M-~>  254,  Hex fe,  Octal 376 ~
 			(where <p> is a special character)
+			
 			The <Nul> character in a file is stored internally as
 			<NL>, but it will be shown as:
 				<^@>  0,  Hex 00,  Octal 000 ~
+				
 			If the character has composing characters these are
 			also shown.  The value of 'maxcombine' doesn't matter.
-			Mnemonic: Get ASCII value.
+			
+			If the character can be inserted as a digraph, also
+			output the two characters that can be used to create
+			the character:
+			    <ö> 246, Hex 00f6, Oct 366, Digr o: ~
+			This shows you can type CTRL-K o : to insert ö.
+
 
 							*g8*
 g8			Print the hex values of the bytes used in the
diff --git a/src/nvim/digraph.c b/src/nvim/digraph.c
index 5a491877a4..3329290634 100644
--- a/src/nvim/digraph.c
+++ b/src/nvim/digraph.c
@@ -1397,7 +1397,7 @@ static digr_T digraphdefault[] =
   { 'O', '`', 210 },  // �
   { 'O', '^', 212 },  // �
   { 'O', '~', 213 },  // �
-  { '/', '\\', 215 }, // � - multiplication symbol in ISO 8859-1
+  { '/', '\\', 215 },  // � - multiplication symbol in ISO 8859-1
   { 'U', '`', 217 },  // �
   { 'U', '^', 219 },  // �
   { 'I', 'p', 222 },  // �
@@ -1448,6 +1448,33 @@ int do_digraph(int c)
   return c;
 }
 
+/// Find a digraph for "val".  If found return the string to display it.
+/// If not found return NULL.
+char_u *get_digraph_for_char(int val)
+{
+  digr_T *dp;
+  static char_u r[3];
+
+  for (int use_defaults = 0; use_defaults <= 1; use_defaults++) {
+    if (use_defaults == 0) {
+      dp = (digr_T *)user_digraphs.ga_data;
+    } else {
+      dp = digraphdefault;
+    }
+    for (int i = 0;
+         use_defaults ? dp->char1 != NUL : i < user_digraphs.ga_len; i++) {
+      if (dp->result == val) {
+        r[0] = dp->char1;
+        r[1] = dp->char2;
+        r[2] = NUL;
+        return r;
+      }
+      dp++;
+    }
+  }
+  return NULL;
+}
+
 /// Get a digraph.  Used after typing CTRL-K on the command line or in normal
 /// mode.
 ///
diff --git a/src/nvim/ex_cmds.c b/src/nvim/ex_cmds.c
index 99f8963dad..dc942eb0b3 100644
--- a/src/nvim/ex_cmds.c
+++ b/src/nvim/ex_cmds.c
@@ -114,6 +114,7 @@ typedef struct {
 /// ":ascii" and "ga" implementation
 void do_ascii(const exarg_T *const eap)
 {
+  char_u *dig;
   int cc[MAX_MCO];
   int c = utfc_ptr2char(get_cursor_pos_ptr(), cc);
   if (c == NUL) {
@@ -141,10 +142,22 @@ void do_ascii(const exarg_T *const eap)
     }
     char buf2[20];
     buf2[0] = NUL;
-    iobuff_len += (
-        vim_snprintf((char *)IObuff + iobuff_len, sizeof(IObuff) - iobuff_len,
-                     _("<%s>%s%s  %d,  Hex %02x,  Octal %03o"),
-                     transchar(c), buf1, buf2, cval, cval, cval));
+
+    dig = get_digraph_for_char(cval);
+    if (dig != NULL) {
+        iobuff_len += (
+            vim_snprintf((char *)IObuff + iobuff_len,
+                         sizeof(IObuff) - iobuff_len,
+                         _("<%s>%s%s  %d,  Hex %02x,  Oct %03o, Digr %s"),
+                         transchar(c), buf1, buf2, cval, cval, cval, dig));
+    } else {
+        iobuff_len += (
+            vim_snprintf((char *)IObuff + iobuff_len,
+                         sizeof(IObuff) - iobuff_len,
+                         _("<%s>%s%s  %d,  Hex %02x,  Octal %03o"),
+                         transchar(c), buf1, buf2, cval, cval, cval));
+    }
+
     c = cc[ci++];
   }
 
@@ -179,11 +192,25 @@ void do_ascii(const exarg_T *const eap)
       IObuff[iobuff_len++] = ' ';  // Draw composing char on top of a space.
     }
     iobuff_len += utf_char2bytes(c, IObuff + iobuff_len);
-    iobuff_len += (
-        vim_snprintf((char *)IObuff + iobuff_len, sizeof(IObuff) - iobuff_len,
-                     (c < 0x10000
-                      ? _("> %d, Hex %04x, Octal %o")
-                      : _("> %d, Hex %08x, Octal %o")), c, c, c));
+
+    dig = get_digraph_for_char(c);
+    if (dig != NULL) {
+        iobuff_len += (
+            vim_snprintf((char *)IObuff + iobuff_len,
+                         sizeof(IObuff) - iobuff_len,
+                         (c < 0x10000
+                          ? _("> %d, Hex %04x, Oct %o, Digr %s")
+                          : _("> %d, Hex %08x, Oct %o, Digr %s")),
+                         c, c, c, dig));
+    } else {
+        iobuff_len += (
+            vim_snprintf((char *)IObuff + iobuff_len,
+                         sizeof(IObuff) - iobuff_len,
+                         (c < 0x10000
+                          ? _("> %d, Hex %04x, Octal %o")
+                          : _("> %d, Hex %08x, Octal %o")),
+                         c, c, c));
+    }
     if (ci == MAX_MCO) {
       break;
     }
diff --git a/src/nvim/testdir/shared.vim b/src/nvim/testdir/shared.vim
index b2fe9413e8..b1f1d8fe66 100644
--- a/src/nvim/testdir/shared.vim
+++ b/src/nvim/testdir/shared.vim
@@ -237,3 +237,14 @@ func RunVimPiped(before, after, arguments, pipecmd)
   endif
   return 1
 endfunc
+
+" Get line "lnum" as displayed on the screen.
+" Trailing white space is trimmed.
+func! Screenline(lnum)
+  let chars = []
+  for c in range(1, winwidth(0))
+    call add(chars, nr2char(screenchar(a:lnum, c)))
+  endfor
+  let line = join(chars, '')
+  return matchstr(line, '^.\{-}\ze\s*$')
+endfunc
diff --git a/src/nvim/testdir/test_arabic.vim b/src/nvim/testdir/test_arabic.vim
index e62b022632..17e925ee7f 100644
--- a/src/nvim/testdir/test_arabic.vim
+++ b/src/nvim/testdir/test_arabic.vim
@@ -16,9 +16,9 @@ func s:get_chars(lnum)
   let numchars = strchars(getline('.'), 1)
   for i in range(1, numchars)
     exe 'norm ' i . '|'
-    let c=execute('ascii')
-    let c=substitute(c, '\n\?<.\{-}Hex\s*', 'U+', 'g')
-    let c=substitute(c, ',\s*Octal\s*\d*', '', 'g')
+    let c = execute('ascii')
+    let c = substitute(c, '\n\?<.\{-}Hex\s*', 'U+', 'g')
+    let c = substitute(c, ',\s*Oct\(al\)\=\s\d*\(, Digr ..\)\=', '', 'g')
     call add(chars, c)
   endfor
   return chars
diff --git a/src/nvim/testdir/test_digraph.vim b/src/nvim/testdir/test_digraph.vim
index 6290680305..271066df41 100644
--- a/src/nvim/testdir/test_digraph.vim
+++ b/src/nvim/testdir/test_digraph.vim
@@ -4,15 +4,15 @@ if !has("digraphs") || !has("multi_byte")
   finish
 endif
 
-func! Put_Dig(chars)
+func Put_Dig(chars)
   exe "norm! o\<c-k>".a:chars
 endfu
 
-func! Put_Dig_BS(char1, char2)
+func Put_Dig_BS(char1, char2)
   exe "norm! o".a:char1."\<bs>".a:char2
 endfu
 
-func! Test_digraphs()
+func Test_digraphs()
   new
   call Put_Dig("00")
   call assert_equal("∞", getline('.'))
@@ -214,7 +214,7 @@ func! Test_digraphs()
   bw!
 endfunc
 
-func! Test_digraphs_option()
+func Test_digraphs_option()
   " reset whichwrap option, so that testing <esc><bs>A works,
   " without moving up a line
   set digraph ww=
@@ -420,7 +420,7 @@ func! Test_digraphs_option()
   bw!
 endfunc
 
-func! Test_digraphs_output()
+func Test_digraphs_output()
   new
   let out = execute(':digraph')
   call assert_equal('Eu €  8364',  matchstr(out, '\C\<Eu\D*8364\>'))
@@ -436,7 +436,7 @@ func! Test_digraphs_output()
   bw!
 endfunc
 
-func! Test_loadkeymap()
+func Test_loadkeymap()
   if !has('keymap')
     return
   endif
@@ -450,7 +450,7 @@ func! Test_loadkeymap()
   bw!
 endfunc
 
-func! Test_digraph_cmndline()
+func Test_digraph_cmndline()
   " Create digraph on commandline
   " This is a hack, to let Vim create the digraph in commandline mode
   let s = ''
@@ -458,4 +458,11 @@ func! Test_digraph_cmndline()
   call assert_equal("€", s)
 endfunc
 
+func Test_show_digraph()
+  new
+  call Put_Dig("e=")
+  call assert_equal("\n<е> 1077, Hex 0435, Oct 2065, Digr e=", execute('ascii'))
+  bwipe!
+endfunc
+
 " vim: shiftwidth=2 sts=2 expandtab
diff --git a/src/nvim/testdir/test_ga.vim b/src/nvim/testdir/test_ga.vim
index f9357ddc87..6a7cba28f0 100644
--- a/src/nvim/testdir/test_ga.vim
+++ b/src/nvim/testdir/test_ga.vim
@@ -11,13 +11,13 @@ func Test_ga_command()
   new
   set display=uhex
   call assert_equal("\nNUL",                            Do_ga(''))
-  call assert_equal("\n<<01>>  1,  Hex 01,  Octal 001", Do_ga("\x01"))
-  call assert_equal("\n<<09>>  9,  Hex 09,  Octal 011", Do_ga("\t"))
+  call assert_equal("\n<<01>>  1,  Hex 01,  Oct 001, Digr SH", Do_ga("\x01"))
+  call assert_equal("\n<<09>>  9,  Hex 09,  Oct 011, Digr HT", Do_ga("\t"))
 
   set display=
   call assert_equal("\nNUL",                             Do_ga(''))
-  call assert_equal("\n<^A>  1,  Hex 01,  Octal 001",    Do_ga("\x01"))
-  call assert_equal("\n<^I>  9,  Hex 09,  Octal 011",    Do_ga("\t"))
+  call assert_equal("\n<^A>  1,  Hex 01,  Oct 001, Digr SH",    Do_ga("\x01"))
+  call assert_equal("\n<^I>  9,  Hex 09,  Oct 011, Digr HT",    Do_ga("\t"))
 
   call assert_equal("\n<e>  101,  Hex 65,  Octal 145",   Do_ga('e'))
 
@@ -26,8 +26,8 @@ func Test_ga_command()
   endif
 
   " Test a few multi-bytes characters.
-  call assert_equal("\n<é> 233, Hex 00e9, Octal 351",    Do_ga('é'))
-  call assert_equal("\n<ẻ> 7867, Hex 1ebb, Octal 17273", Do_ga('ẻ'))
+  call assert_equal("\n<é> 233, Hex 00e9, Oct 351, Digr e'",    Do_ga('é'))
+  call assert_equal("\n<ẻ> 7867, Hex 1ebb, Oct 17273, Digr e2", Do_ga('ẻ'))
 
   " Test with combining characters.
   call assert_equal("\n<e>  101,  Hex 65,  Octal 145 < ́> 769, Hex 0301, Octal 1401", Do_ga("e\u0301"))
diff --git a/src/nvim/testdir/test_matchadd_conceal.vim b/src/nvim/testdir/test_matchadd_conceal.vim
index c11f1a84a9..b918525dbc 100644
--- a/src/nvim/testdir/test_matchadd_conceal.vim
+++ b/src/nvim/testdir/test_matchadd_conceal.vim
@@ -3,17 +3,7 @@ if !has('conceal')
   finish
 endif
 
-function! s:screenline(lnum) abort
-  let line = []
-  for c in range(1, winwidth(0))
-    call add(line, nr2char(screenchar(a:lnum, c)))
-  endfor
-  return s:trim(join(line, ''))
-endfunction
-
-function! s:trim(str) abort
-  return matchstr(a:str,'^\s*\zs.\{-}\ze\s*$')
-endfunction
+source shared.vim
 
 function! Test_simple_matchadd()
   new
@@ -26,7 +16,7 @@ function! Test_simple_matchadd()
   call matchadd('Conceal', '\%2l ')
   redraw!
   let lnum = 2
-  call assert_equal(expect, s:screenline(lnum))
+  call assert_equal(expect, Screenline(lnum))
   call assert_notequal(screenattr(lnum, 1), screenattr(lnum, 2))
   call assert_notequal(screenattr(lnum, 1), screenattr(lnum, 2))
   call assert_equal(screenattr(lnum, 2), screenattr(lnum, 7))
@@ -49,7 +39,7 @@ function! Test_simple_matchadd_and_conceal()
   call matchadd('Conceal', '\%2l ', 10, -1, {'conceal': 'X'})
   redraw!
   let lnum = 2
-  call assert_equal(expect, s:screenline(lnum))
+  call assert_equal(expect, Screenline(lnum))
   call assert_notequal(screenattr(lnum, 1), screenattr(lnum, 2))
   call assert_equal(screenattr(lnum, 2), screenattr(lnum, 7))
   call assert_equal(screenattr(lnum, 2), screenattr(lnum, 10))
@@ -75,7 +65,7 @@ function! Test_matchadd_and_conceallevel_3()
   call matchadd('Conceal', '\%2l ', 10, -1, {'conceal': 'X'})
   redraw!
   let lnum = 2
-  call assert_equal(expect, s:screenline(lnum))
+  call assert_equal(expect, Screenline(lnum))
   call assert_equal(screenattr(lnum, 1), screenattr(lnum, 2))
   call assert_equal(screenattr(lnum, 2), screenattr(lnum, 7))
   call assert_equal(screenattr(lnum, 2), screenattr(lnum, 10))
@@ -88,7 +78,7 @@ function! Test_matchadd_and_conceallevel_3()
 
   call matchadd('ErrorMsg', '\%2l Test', 20, -1, {'conceal': 'X'})
   redraw!
-  call assert_equal(expect, s:screenline(lnum))
+  call assert_equal(expect, Screenline(lnum))
   call assert_equal(screenattr(lnum, 1) , screenattr(lnum, 2))
   call assert_equal(screenattr(lnum, 2) , screenattr(lnum, 7))
   call assert_notequal(screenattr(lnum, 1) , screenattr(lnum, 10))
@@ -112,7 +102,7 @@ function! Test_default_conceal_char()
   call matchadd('Conceal', '\%2l ', 10, -1, {})
   redraw!
   let lnum = 2
-  call assert_equal(expect, s:screenline(lnum))
+  call assert_equal(expect, Screenline(lnum))
   call assert_notequal(screenattr(lnum, 1), screenattr(lnum, 2))
   call assert_equal(screenattr(lnum, 2), screenattr(lnum, 7))
   call assert_equal(screenattr(lnum, 2), screenattr(lnum, 10))
@@ -125,7 +115,7 @@ function! Test_default_conceal_char()
   set listchars=conceal:+
   redraw!
 
-  call assert_equal(expect, s:screenline(lnum))
+  call assert_equal(expect, Screenline(lnum))
   call assert_notequal(screenattr(lnum, 1), screenattr(lnum, 2))
   call assert_equal(screenattr(lnum, 2), screenattr(lnum, 7))
   call assert_equal(screenattr(lnum, 2), screenattr(lnum, 10))
@@ -149,7 +139,7 @@ function! Test_syn_and_match_conceal()
   syntax match MyConceal /\%2l / conceal containedin=ALL cchar=*
   redraw!
   let lnum = 2
-  call assert_equal(expect, s:screenline(lnum))
+  call assert_equal(expect, Screenline(lnum))
   call assert_notequal(screenattr(lnum, 1), screenattr(lnum, 2))
   call assert_equal(screenattr(lnum, 2), screenattr(lnum, 7))
   call assert_equal(screenattr(lnum, 2), screenattr(lnum, 10))
@@ -161,7 +151,7 @@ function! Test_syn_and_match_conceal()
   call clearmatches()
   redraw!
 
-  call assert_equal(expect, s:screenline(lnum))
+  call assert_equal(expect, Screenline(lnum))
   call assert_notequal(screenattr(lnum, 1), screenattr(lnum, 2))
   call assert_equal(screenattr(lnum, 2), screenattr(lnum, 7))
   call assert_equal(screenattr(lnum, 2), screenattr(lnum, 10))
@@ -187,7 +177,7 @@ function! Test_clearmatches()
   redraw!
 
   let lnum = 2
-  call assert_equal(expect, s:screenline(lnum))
+  call assert_equal(expect, Screenline(lnum))
   call assert_equal(screenattr(lnum, 1), screenattr(lnum, 2))
   call assert_equal(screenattr(lnum, 2), screenattr(lnum, 7))
   call assert_equal(screenattr(lnum, 2), screenattr(lnum, 10))
@@ -200,7 +190,7 @@ function! Test_clearmatches()
   call setmatches(a)
   redraw!
 
-  call assert_equal(expect, s:screenline(lnum))
+  call assert_equal(expect, Screenline(lnum))
   call assert_notequal(screenattr(lnum, 1), screenattr(lnum, 2))
   call assert_equal(screenattr(lnum, 2), screenattr(lnum, 7))
   call assert_equal(screenattr(lnum, 2), screenattr(lnum, 10))
@@ -228,7 +218,7 @@ function! Test_using_matchaddpos()
   redraw!
 
   let lnum = 2
-  call assert_equal(expect, s:screenline(lnum))
+  call assert_equal(expect, Screenline(lnum))
   call assert_notequal(screenattr(lnum, 1) , screenattr(lnum, 2))
   call assert_notequal(screenattr(lnum, 2) , screenattr(lnum, 7))
   call assert_equal(screenattr(lnum, 1) , screenattr(lnum, 7))
@@ -250,13 +240,13 @@ function! Test_matchadd_repeat_conceal_with_syntax_off()
   1put ='TARGET_TARGETTARGET'
   call cursor(1, 1)
   redraw
-  call assert_equal('TARGET_TARGETTARGET', s:screenline(2))
+  call assert_equal('TARGET_TARGETTARGET', Screenline(2))
 
   setlocal conceallevel=2
   call matchadd('Conceal', 'TARGET', 10, -1, {'conceal': 't'})
 
   redraw
-  call assert_equal('t_tt', s:screenline(2))
+  call assert_equal('t_tt', Screenline(2))
 
   quit!
 endfunction
@@ -272,13 +262,13 @@ function! Test_matchadd_and_syn_conceal()
   syntax on
   syntax keyword coqKwd bool conceal cchar=-
   redraw!
-  call assert_equal(expect, s:screenline(1))
+  call assert_equal(expect, Screenline(1))
   call assert_notequal(screenattr(1, 10) , screenattr(1, 11))
   call assert_notequal(screenattr(1, 11) , screenattr(1, 12))
   call assert_equal(screenattr(1, 11) , screenattr(1, 32))
   call matchadd('CheckedByCoq', '\%<2l\%>9c\%<16c')
   redraw!
-  call assert_equal(expect, s:screenline(1))
+  call assert_equal(expect, Screenline(1))
   call assert_notequal(screenattr(1, 10) , screenattr(1, 11))
   call assert_notequal(screenattr(1, 11) , screenattr(1, 12))
   call assert_equal(screenattr(1, 11) , screenattr(1, 32))