vim-patch:8.2.3265: smartcase does not work correctly in very magic pattern

Problem:    Smartcase does not work correctly in very magic pattern.
Solution:   Take the magicness into account when skipping over regexp items.
            (Christian Brabandt, closes vim/vim#8682, closes vim/vim#7845)

78ba933d18

Co-authored-by: Christian Brabandt <cb@256bit.org>

src/nvim/search.c

@@ -373,6 +373,10 @@ bool pat_has_uppercase(char_u *pat)
   FUNC_ATTR_NONNULL_ALL
 {
   char_u *p = pat;
+  magic_T magic_val = MAGIC_ON;
+
+  // get the magicness of the pattern
+  (void)skip_regexp_ex((char *)pat, NUL, magic_isset(), NULL, NULL, &magic_val);
 
   while (*p != NUL) {
     const int l = utfc_ptr2len((char *)p);
@@ -382,7 +386,7 @@ bool pat_has_uppercase(char_u *pat)
         return true;
       }
       p += l;
-    } else if (*p == '\\') {
+    } else if (*p == '\\' && magic_val == MAGIC_ON) {
       if (p[1] == '_' && p[2] != NUL) {  // skip "\_X"
         p += 3;
       } else if (p[1] == '%' && p[2] != NUL) {  // skip "\%X"
@@ -392,6 +396,10 @@ bool pat_has_uppercase(char_u *pat)
       } else {
         p += 1;
       }
+    } else if ((*p == '%' || *p == '_') && magic_val == MAGIC_ALL) {
+      if (p[1] != NUL) {  // skip "_X" and %X
+        p += 2;
+      }
     } else if (mb_isupper(*p)) {
       return true;
     } else {

src/nvim/testdir/test_search.vim

@@ -1998,6 +1998,60 @@ func Test_incsearch_substitute_dump2()
   call delete('Xis_subst_script2')
 endfunc
 
+func Test_pattern_is_uppercase_smartcase()
+  new
+  let input=['abc', 'ABC', 'Abc', 'abC']
+  call setline(1, input)
+  call cursor(1,1)
+  " default, matches firstline
+  %s/abc//g
+  call assert_equal(['', 'ABC', 'Abc', 'abC'],
+        \ getline(1, '$'))
+
+  set smartcase ignorecase
+  sil %d
+  call setline(1, input)
+  call cursor(1,1)
+  " with smartcase and incsearch set, matches everything
+  %s/abc//g
+  call assert_equal(['', '', '', ''], getline(1, '$'))
+
+  sil %d
+  call setline(1, input)
+  call cursor(1,1)
+  " with smartcase and incsearch set and found an uppercase letter,
+  " match only that.
+  %s/abC//g
+  call assert_equal(['abc', 'ABC', 'Abc', ''],
+        \ getline(1, '$'))
+
+  sil %d
+  call setline(1, input)
+  call cursor(1,1)
+  exe "norm! vG$\<esc>"
+  " \%V should not be detected as uppercase letter
+  %s/\%Vabc//g
+  call assert_equal(['', '', '', ''], getline(1, '$'))
+
+  call setline(1, input)
+  call cursor(1,1)
+  exe "norm! vG$\<esc>"
+  " \v%V should not be detected as uppercase letter
+  %s/\v%Vabc//g
+  call assert_equal(['', '', '', ''], getline(1, '$'))
+
+  call setline(1, input)
+  call cursor(1,1)
+  exe "norm! vG$\<esc>"
+  " \v%VabC should be detected as uppercase letter
+  %s/\v%VabC//g
+  call assert_equal(['abc', 'ABC', 'Abc', ''],
+        \ getline(1, '$'))
+
+  set smartcase& ignorecase&
+  bw!
+endfunc
+
 func Test_no_last_search_pattern()
   CheckOption incsearch