vim-patch:7.4.2230 (#6080)

Problem:    There is no equivalent of 'smartcase' for a tag search.
Solution:   Add value "followscs" and "smart" to 'tagcase'. (Christian
            Brabandt, closes vim/vim#712) Turn tagcase test into new style.

https://github.com/vim/vim/commit/66e29d7112e437b2b50efe1f82c7e892736d23e4

8 files changed, 129 insertions, 21 deletions

diff --git a/runtime/doc/options.txt b/runtime/doc/options.txt
index 4ae4725617..cd257b7780 100644
--- a/runtime/doc/options.txt
+++ b/runtime/doc/options.txt
@@ -6273,6 +6273,9 @@ A jump table for the options with a short description can be found at |Q_op|.
 	By default, tag searches are case-sensitive.  Case is ignored when
 	'ignorecase' is set and 'tagcase' is "followic", or when 'tagcase' is
 	"ignore".
+	Also when 'tagcase' is "followscs" and 'smartcase' is set, or
+	'tagcase' is "smart", and the pattern contains only lowercase
+	characters.
 
 	When 'tagbsearch' is off, tags searching is slower when a full match
 	exists, but faster when no full match exists.  Tags in unsorted tags
@@ -6290,8 +6293,10 @@ A jump table for the options with a short description can be found at |Q_op|.
 	This option specifies how case is handled when searching the tags
 	file:
 	   followic	Follow the 'ignorecase' option
+	   followscs    Follow the 'smartcase' and 'ignorecase' options
 	   ignore	Ignore case
 	   match	Match case
+	   smart	Ignore case unless an upper case letter is used
 
 						*'taglength'* *'tl'*
 'taglength' 'tl'	number	(default 0)
diff --git a/runtime/doc/tagsrch.txt b/runtime/doc/tagsrch.txt
index 75d820d072..047abb42cc 100644
--- a/runtime/doc/tagsrch.txt
+++ b/runtime/doc/tagsrch.txt
@@ -83,14 +83,23 @@ Note that when the current file changes, the priority list is mostly not
 changed, to avoid confusion when using ":tnext".  It is changed when using
 ":tag {ident}".
 
-The ignore-case matches are not found for a ":tag" command when the
-'ignorecase' option is off and 'tagcase' is "followic" or when 'tagcase' is
-"match".  They are found when a pattern is used (starting with a "/") and for
-":tselect", also when 'ignorecase' is off and 'tagcase' is "followic" or when
-'tagcase' is "match".  Note that using ignore-case tag searching disables
-binary searching in the tags file, which causes a slowdown.  This can be
-avoided by fold-case sorting the tag file.  See the 'tagbsearch' option for an
-explanation.
+The ignore-case matches are not found for a ":tag" command when:
+- the 'ignorecase' option is off and 'tagcase' is "followic"
+- 'tagcase' is "match"
+- 'tagcase' is "smart" and the pattern contains an upper case character.
+- 'tagcase' is "followscs" and 'smartcase' option is on and the pattern
+  contains an upper case character.
+
+The gnore-case matches are found when:
+- a pattern is used (starting with a "/")
+- for ":tselect"
+- when 'tagcase' is "followic" and 'ignorecase' is off
+- when 'tagcase' is "match"
+- when 'tagcase' is "followscs" and the 'smartcase' option is off
+
+Note that using ignore-case tag searching disables binary searching in the
+tags file, which causes a slowdown.  This can be avoided by fold-case sorting
+the tag file. See the 'tagbsearch' option for an explanation.
 
 ==============================================================================
 2. Tag stack				*tag-stack* *tagstack* *E425*
@@ -420,13 +429,18 @@ file "tags".  It can also be used to access a common tags file.
 The next file in the list is not used when:
 - A matching static tag for the current buffer has been found.
 - A matching global tag has been found.
-This also depends on whether case is ignored.  Case is ignored when
-'ignorecase' is set and 'tagcase' is "followic", or when 'tagcase' is
-"ignore".  If case is not ignored, and the tags file only has a match without
-matching case, the next tags file is searched for a match with matching case.
-If no tag with matching case is found, the first match without matching case
-is used.  If case is ignored, and a matching global tag with or without
-matching case is found, this one is used, no further tags files are searched.
+This also depends on whether case is ignored.  Case is ignored when:
+- 'tagcase' is "followic" and 'ignorecase' is set
+- 'tagcase' is "ignore"
+- 'tagcase' is "smart" and and the pattern only contains lower case
+  characters.
+- 'tagcase' is "followscs" and 'smartcase' is set and and the pattern only
+  contains lower case characters.
+If case is not ignored, and the tags file only has a match without matching
+case, the next tags file is searched for a match with matching case.  If no
+tag with matching case is found, the first match without matching case is
+used.  If case is ignored, and a matching global tag with or without matching
+case is found, this one is used, no further tags files are searched.
 
 When a tag file name starts with "./", the '.' is replaced with the path of
 the current file.  This makes it possible to use a tags file in the directory
diff --git a/src/nvim/option_defs.h b/src/nvim/option_defs.h
index 602497461d..d077f5f2f7 100644
--- a/src/nvim/option_defs.h
+++ b/src/nvim/option_defs.h
@@ -601,11 +601,14 @@ EXTERN int p_tbs;               ///< 'tagbsearch'
 EXTERN char_u *p_tc;            ///< 'tagcase'
 EXTERN unsigned tc_flags;       ///< flags from 'tagcase'
 #ifdef IN_OPTION_C
-static char *(p_tc_values[]) = { "followic", "ignore", "match", NULL };
+static char *(p_tc_values[]) =
+  { "followic", "ignore", "match", "followscs", "smart", NULL };
 #endif
 #define TC_FOLLOWIC             0x01
 #define TC_IGNORE               0x02
 #define TC_MATCH                0x04
+#define TC_FOLLOWSCS            0x08
+#define TC_SMART                0x10
 EXTERN long p_tl;               ///< 'taglength'
 EXTERN int p_tr;                ///< 'tagrelative'
 EXTERN char_u *p_tags;          ///< 'tags'
diff --git a/src/nvim/search.c b/src/nvim/search.c
index a9766a406e..ba6c4e6548 100644
--- a/src/nvim/search.c
+++ b/src/nvim/search.c
@@ -308,13 +308,19 @@ void free_search_patterns(void)
  */
 int ignorecase(char_u *pat)
 {
-  int ic = p_ic;
+  return ignorecase_opt(pat, p_ic, p_scs);
+}
 
-  if (ic && !no_smartcase && p_scs
+/// As ignorecase() put pass the "ic" and "scs" flags.
+int ignorecase_opt(char_u *pat, int ic_in, int scs)
+{
+  int ic = ic_in;
+  if (ic && !no_smartcase && scs
       && !(ctrl_x_mode && curbuf->b_p_inf)
-      )
+      ) {
     ic = !pat_has_uppercase(pat);
-  no_smartcase = FALSE;
+  }
+  no_smartcase = false;
 
   return ic;
 }
diff --git a/src/nvim/tag.c b/src/nvim/tag.c
index e723ea20c9..cc5aac6094 100644
--- a/src/nvim/tag.c
+++ b/src/nvim/tag.c
@@ -1164,6 +1164,12 @@ find_tags (
     case TC_MATCH:
       p_ic = false;
       break;
+    case TC_FOLLOWSCS:
+      p_ic = ignorecase(pat);
+      break;
+    case TC_SMART:
+      p_ic = ignorecase_opt(pat, true, true);
+      break;
     default:
       assert(false);
   }
diff --git a/src/nvim/testdir/test_alot.vim b/src/nvim/testdir/test_alot.vim
index 375d8219e6..04cc279619 100644
--- a/src/nvim/testdir/test_alot.vim
+++ b/src/nvim/testdir/test_alot.vim
@@ -25,6 +25,7 @@ source test_statusline.vim
 source test_syn_attr.vim
 source test_tabline.vim
 source test_tabpage.vim
+source test_tagcase.vim
 source test_tagjump.vim
 source test_unlet.vim
 source test_window_cmd.vim
diff --git a/src/nvim/testdir/test_tagcase.vim b/src/nvim/testdir/test_tagcase.vim
new file mode 100644
index 0000000000..833cb9f990
--- /dev/null
+++ b/src/nvim/testdir/test_tagcase.vim
@@ -0,0 +1,73 @@
+" test 'tagcase' option
+
+func Test_tagcase()
+  call writefile(["Bar\tXtext\t3", "Foo\tXtext\t2", "foo\tXtext\t4"], 'Xtags')
+  set tags=Xtags
+  e Xtext
+
+  for &ic in [0, 1]
+    for &scs in [0, 1]
+      for &g:tc in ["followic", "ignore", "match", "followscs", "smart"]
+        for &l:tc in ["", "followic", "ignore", "match", "followscs", "smart"]
+          let smart = 0
+          if &l:tc != ''
+            let tc = &l:tc
+          else
+            let tc = &g:tc
+          endif
+          if tc == 'followic'
+            let ic = &ic
+          elseif tc == 'ignore'
+            let ic = 1
+          elseif tc == 'followscs'
+            let ic = &ic
+            let smart = &scs
+          elseif tc == 'smart'
+            let ic = 1
+            let smart = 1
+          else
+            let ic = 0
+          endif
+          if ic && smart
+            call assert_equal(['foo', 'Foo'], map(taglist("^foo$"), {i, v -> v.name}))
+            call assert_equal(['Foo'], map(taglist("^Foo$"), {i, v -> v.name}))
+          elseif ic
+            call assert_equal(['foo', 'Foo'], map(taglist("^foo$"), {i, v -> v.name}))
+            call assert_equal(['Foo', 'foo'], map(taglist("^Foo$"), {i, v -> v.name}))
+          else
+            call assert_equal(['foo'], map(taglist("^foo$"), {i, v -> v.name}))
+            call assert_equal(['Foo'], map(taglist("^Foo$"), {i, v -> v.name}))
+          endif
+        endfor
+      endfor
+    endfor
+  endfor
+
+  call delete('Xtags')
+  set ic&
+  setg tc&
+  setl tc&
+  set scs&
+endfunc
+
+func Test_set_tagcase()
+  " Verify default values.
+  set ic&
+  setg tc&
+  setl tc&
+  call assert_equal(0, &ic)
+  call assert_equal('followic', &g:tc)
+  call assert_equal('followic', &l:tc)
+  call assert_equal('followic', &tc)
+
+  " Verify that the local setting accepts <empty> but that the global setting
+  " does not.  The first of these (setting the local value to <empty>) should
+  " succeed; the other two should fail.
+  setl tc=
+  call assert_fails('setg tc=', 'E474:')
+  call assert_fails('set tc=', 'E474:')
+
+  set ic&
+  setg tc&
+  setl tc&
+endfunc
diff --git a/src/nvim/version.c b/src/nvim/version.c
index 3787ba6908..fe443ce01f 100644
--- a/src/nvim/version.c
+++ b/src/nvim/version.c
@@ -210,7 +210,7 @@ static int included_patches[] = {
   2233,
   // 2232 NA
   // 2231,
-  // 2230,
+  2230,
   // 2229,
   // 2228,
   2227,