vim-patch:8.1.0295: no 'incsearch' highlighting for :vimgrep and similar

Problem:    No 'incsearch' highlighting for :vimgrep and similar commands.
Solution:   Parse the :vimgrep command and similar ones to locate the search
            pattern. (Hirohito Higashi, closes vim/vim#3344)
https://github.com/vim/vim/commit/264cf5cfaf40e704aea2578e70c15ed9a9d0161e

3 files changed, 149 insertions, 31 deletions

diff --git a/src/nvim/ex_getln.c b/src/nvim/ex_getln.c
index 95348de320..8e7d114820 100644
--- a/src/nvim/ex_getln.c
+++ b/src/nvim/ex_getln.c
@@ -307,48 +307,67 @@ static bool do_incsearch_highlighting(int firstc, incsearch_state_T *s,
       cmdmod = save_cmdmod;
 
       cmd = skip_range(ea.cmd, NULL);
-      if (*cmd == 's' || *cmd == 'g' || *cmd == 'v') {
+      if (*cmd == 's' || *cmd == 'g' || *cmd == 'v' || *cmd == 'l') {
         // Skip over "substitute" to find the pattern separator.
         for (p = cmd; ASCII_ISALPHA(*p); p++) {}
-        if (*skipwhite(p) != NUL
-            && (STRNCMP(cmd, "substitute", p - cmd) == 0
-                || STRNCMP(cmd, "smagic", p - cmd) == 0
-                || STRNCMP(cmd, "snomagic", MAX(p - cmd, 3)) == 0
-                || STRNCMP(cmd, "sort", p - cmd) == 0
-                || STRNCMP(cmd, "global", p - cmd) == 0
-                || STRNCMP(cmd, "vglobal", p - cmd) == 0)) {
-          if (*cmd == 's' && cmd[1] == 'm') {
-            p_magic = true;
-          }
-          else if (*cmd == 's' && cmd[1] == 'n') {
-            p_magic = false;
-          }
+        if (*skipwhite(p) != NUL) {
+          if (STRNCMP(cmd, "substitute", p - cmd) == 0
+              || STRNCMP(cmd, "smagic", p - cmd) == 0
+              || STRNCMP(cmd, "snomagic", MAX(p - cmd, 3)) == 0
+              || STRNCMP(cmd, "sort", MAX(p - cmd,3)) == 0
+              || STRNCMP(cmd, "global", p - cmd) == 0
+              || STRNCMP(cmd, "vglobal", p - cmd) == 0) {
+            if (*cmd == 's' && cmd[1] == 'm') {
+              p_magic = true;
+            }
+            else if (*cmd == 's' && cmd[1] == 'n') {
+              p_magic = false;
+            }
 
-          // Check for "global!/".
-          if (*cmd == 'g' && *p == '!') {
-            p++;
-            if (*skipwhite(p) == NUL) {
-              return false;
+            // Check for "global!/".
+            if (*cmd == 'g' && *p == '!') {
+              p++;
+              if (*skipwhite(p) == NUL) {
+                return false;
+              }
             }
-          }
 
-          // For ":sort" skip over flags.
-          if (cmd[0] == 's' && cmd[1] == 'o') {
-            while (ASCII_ISALPHA(*(p = skipwhite(p)))) {
-              ++p;
+            // For ":sort" skip over flags.
+            if (cmd[0] == 's' && cmd[1] == 'o') {
+              while (ASCII_ISALPHA(*(p = skipwhite(p)))) {
+                ++p;
+              }
+              if (*p == NUL) {
+                return false;
+              }
             }
-            if (*p == NUL) {
-              return false;
+
+            p = skipwhite(p);
+            delim = *p++;
+            end = skip_regexp(p, delim, p_magic, NULL);
+          } else if (STRNCMP(cmd, "vimgrep", MAX(p - cmd, 3)) == 0
+                     || STRNCMP(cmd, "vimgrepadd", MAX(p - cmd, 8)) == 0
+                     || STRNCMP(cmd, "lvimgrep", MAX(p - cmd, 2)) == 0
+                     || STRNCMP(cmd, "lvimgrepadd", MAX(p - cmd, 9)) == 0) {
+            // Check for "!/".
+            if (*p == '!') {
+              p++;
+              if (*skipwhite(p) == NUL) {
+                return false;
+              }
             }
+            p = skipwhite(p);
+            delim = (vim_isIDc(*p)) ? ' ' : *p++;
+            end = skip_regexp(p, delim, p_magic, NULL);
+          }
+          else {
+            end = p;
+            delim = -1;
           }
-
-          p = skipwhite(p);
-          delim = *p++;
-          end = skip_regexp(p, delim, p_magic, NULL);
           if (end > p || *end == delim) {
             pos_T save_cursor = curwin->w_cursor;
 
-            // found a non-empty pattern
+            // found a non-empty pattern or //
             *skiplen = (int)(p - ccline.cmdbuff);
             *patlen = (int)(end - p);
 
diff --git a/src/nvim/testdir/test_search.vim b/src/nvim/testdir/test_search.vim
index 96315faf2d..ef25a3c14d 100644
--- a/src/nvim/testdir/test_search.vim
+++ b/src/nvim/testdir/test_search.vim
@@ -719,6 +719,53 @@ func Test_incsearch_ssort_dump()
   call delete('Xis_sort_script')
 endfunc
 
+" Similar to Test_incsearch_substitute_dump() for :vimgrep famiry
+func Test_incsearch_vimgrep_dump()
+  if !exists('+incsearch')
+    return
+  endif
+  if !CanRunVimInTerminal()
+    throw 'Skipped: cannot make screendumps'
+  endif
+  call writefile([
+	\ 'set incsearch hlsearch scrolloff=0',
+	\ 'call setline(1, ["another one 2", "that one 3", "the one 1"])',
+	\ ], 'Xis_vimgrep_script')
+  let buf = RunVimInTerminal('-S Xis_vimgrep_script', {'rows': 9, 'cols': 70})
+  " Give Vim a chance to redraw to get rid of the spaces in line 2 caused by
+  " the 'ambiwidth' check.
+  sleep 100m
+
+  " Need to send one key at a time to force a redraw.
+  call term_sendkeys(buf, ':vimgrep on')
+  sleep 100m
+  call VerifyScreenDump(buf, 'Test_incsearch_vimgrep_01', {})
+  call term_sendkeys(buf, "\<Esc>")
+
+  call term_sendkeys(buf, ':vimg /on/ *.txt')
+  sleep 100m
+  call VerifyScreenDump(buf, 'Test_incsearch_vimgrep_02', {})
+  call term_sendkeys(buf, "\<Esc>")
+
+  call term_sendkeys(buf, ':vimgrepadd "\<on')
+  sleep 100m
+  call VerifyScreenDump(buf, 'Test_incsearch_vimgrep_03', {})
+  call term_sendkeys(buf, "\<Esc>")
+
+  call term_sendkeys(buf, ':lv "tha')
+  sleep 100m
+  call VerifyScreenDump(buf, 'Test_incsearch_vimgrep_04', {})
+  call term_sendkeys(buf, "\<Esc>")
+
+  call term_sendkeys(buf, ':lvimgrepa "the" **/*.txt')
+  sleep 100m
+  call VerifyScreenDump(buf, 'Test_incsearch_vimgrep_05', {})
+  call term_sendkeys(buf, "\<Esc>")
+
+  call StopVimInTerminal(buf)
+  call delete('Xis_vimgrep_script')
+endfunc
+
 func Test_incsearch_with_change()
   if !has('timers') || !exists('+incsearch') || !CanRunVimInTerminal()
     throw 'Skipped: cannot make screendumps and/or timers feature and/or incsearch option missing'
diff --git a/test/functional/legacy/search_spec.lua b/test/functional/legacy/search_spec.lua
index 0802b43689..bb039a585c 100644
--- a/test/functional/legacy/search_spec.lua
+++ b/test/functional/legacy/search_spec.lua
@@ -587,4 +587,56 @@ describe('search cmdline', function()
     ]])
     feed('<esc>')
   end)
+
+  it('incsearch works with :vimgrep family', function()
+    -- oldtest: Test_incsearch_vimgrep_dump().
+    screen:try_resize(30, 4)
+    command('set incsearch hlsearch scrolloff=0')
+    funcs.setline(1, {'another one 2', 'that one 3', 'the one 1'})
+
+    feed(':vimgrep on')
+    screen:expect([[
+      another {inc:on}e 2                 |
+      that {hl:on}e 3                    |
+      the {hl:on}e 1                     |
+      :vimgrep on^                   |
+    ]])
+    feed('<esc>')
+
+    feed(':vimg /on/ *.txt')
+    screen:expect([[
+      another {inc:on}e 2                 |
+      that {hl:on}e 3                    |
+      the {hl:on}e 1                     |
+      :vimg /on/ *.txt^              |
+    ]])
+    feed('<esc>')
+
+    feed(':vimgrepadd "\\<LT>on')
+    screen:expect([[
+      another {inc:on}e 2                 |
+      that {hl:on}e 3                    |
+      the {hl:on}e 1                     |
+      :vimgrepadd "\<on^             |
+    ]])
+    feed('<esc>')
+
+    feed(':lv "tha')
+    screen:expect([[
+      another one 2                 |
+      {inc:tha}t one 3                    |
+      the one 1                     |
+      :lv "tha^                      |
+    ]])
+    feed('<esc>')
+
+    feed(':lvimgrepa "the" **/*.txt')
+    screen:expect([[
+      ano{inc:the}r one 2                 |
+      that one 3                    |
+      {hl:the} one 1                     |
+      :lvimgrepa "the" **/*.txt^     |
+    ]])
+    feed('<esc>')
+  end)
 end)