vim-patch:8.0.1469: when package path is a symlink 'runtimepath' is wrong

Problem:    When package path is a symlink adding it to 'runtimepath' happens
            at the end.
Solution:   Do not resolve symlinks before locating the position in
            'runtimepath'. (Ozaki Kiichi, closes vim/vim#2604)
https://github.com/vim/vim/commit/2374faae111057ee28e8d487f9a52a95855e2206

2 files changed, 185 insertions, 113 deletions

diff --git a/src/nvim/ex_cmds2.c b/src/nvim/ex_cmds2.c
index c9b6d19aaa..4e3fc86539 100644
--- a/src/nvim/ex_cmds2.c
+++ b/src/nvim/ex_cmds2.c
@@ -2536,137 +2536,163 @@ static void source_all_matches(char_u *pat)
   }
 }
 
-// used for "cookie" of add_pack_plugin()
-static int APP_ADD_DIR;
-static int APP_LOAD;
-static int APP_BOTH;
-
-static void add_pack_plugin(char_u *fname, void *cookie)
+/// Add the package directory to 'runtimepath'
+static int add_pack_dir_to_rtp(char_u *fname)
 {
   char_u *p4, *p3, *p2, *p1, *p;
   char_u *buf = NULL;
+  char *afterdir = NULL;
+  int retval = FAIL;
+
+  p4 = p3 = p2 = p1 = get_past_head(fname);
+  for (p = p1; *p; MB_PTR_ADV(p)) {
+    if (vim_ispathsep_nocolon(*p)) {
+      p4 = p3; p3 = p2; p2 = p1; p1 = p;
+    }
+  }
 
+  // now we have:
+  // rtp/pack/name/start/name
+  //    p4   p3   p2   p1
+  //
+  // find the part up to "pack" in 'runtimepath'
+  p4++;  // append pathsep in order to expand symlink
+  char_u c = *p4;
+  *p4 = NUL;
   char *const ffname = fix_fname((char *)fname);
+  *p4 = c;
 
   if (ffname == NULL) {
-    return;
+    return FAIL;
   }
 
-  if (cookie != &APP_LOAD && strstr((char *)p_rtp, ffname) == NULL) {
-    // directory is not yet in 'runtimepath', add it
-    p4 = p3 = p2 = p1 = get_past_head((char_u *)ffname);
-    for (p = p1; *p; MB_PTR_ADV(p)) {
-      if (vim_ispathsep_nocolon(*p)) {
-        p4 = p3; p3 = p2; p2 = p1; p1 = p;
-      }
-    }
-
-    // now we have:
-    // rtp/pack/name/start/name
-    //    p4   p3   p2   p1
-    //
-    // find the part up to "pack" in 'runtimepath'
-    char_u c = *p4;
-    *p4 = NUL;
-
-    // Find "ffname" in "p_rtp", ignoring '/' vs '\' differences
-    size_t fname_len = strlen(ffname);
-    const char *insp = (const char *)p_rtp;
-    buf = try_malloc(MAXPATHL);
-    if (buf == NULL) {
+  // Find "ffname" in "p_rtp", ignoring '/' vs '\' differences
+  size_t fname_len = strlen(ffname);
+  const char *insp = (const char *)p_rtp;
+  buf = try_malloc(MAXPATHL);
+  if (buf == NULL) {
+    goto theend;
+  }
+  while (*insp != NUL) {
+    copy_option_part((char_u **)&insp, buf, MAXPATHL, ",");
+    add_pathsep((char *)buf);
+    char *const rtp_ffname = fix_fname((char *)buf);
+    if (rtp_ffname == NULL) {
       goto theend;
     }
-    while (*insp != NUL) {
-      copy_option_part((char_u **)&insp, buf, MAXPATHL, ",");
-      add_pathsep((char *)buf);
-      char *const rtp_ffname = fix_fname((char *)buf);
-      if (rtp_ffname == NULL) {
-        goto theend;
-      }
-      bool match = path_fnamencmp(rtp_ffname, ffname, fname_len) == 0;
-      xfree(rtp_ffname);
-      if (match) {
-        break;
-      }
+    bool match = path_fnamencmp(rtp_ffname, ffname, fname_len) == 0;
+    xfree(rtp_ffname);
+    if (match) {
+      break;
     }
+  }
 
-    if (*insp == NUL) {
-      // not found, append at the end
-      insp = (const char *)p_rtp + STRLEN(p_rtp);
-    } else {
-      // append after the matching directory.
-      insp--;
-    }
-    *p4 = c;
+  if (*insp == NUL) {
+    // not found, append at the end
+    insp = (const char *)p_rtp + STRLEN(p_rtp);
+  } else {
+    // append after the matching directory.
+    insp--;
+  }
 
-    // check if rtp/pack/name/start/name/after exists
-    char *afterdir = concat_fnames(ffname, "after", true);
-    size_t afterlen = 0;
-    if (os_isdir((char_u *)afterdir)) {
-      afterlen = strlen(afterdir) + 1;  // add one for comma
-    }
+  // check if rtp/pack/name/start/name/after exists
+  afterdir = concat_fnames((char *)fname, "after", true);
+  size_t afterlen = 0;
+  if (os_isdir((char_u *)afterdir)) {
+    afterlen = strlen(afterdir) + 1;  // add one for comma
+  }
 
-    const size_t oldlen = STRLEN(p_rtp);
-    const size_t addlen = strlen(ffname) + 1;  // add one for comma
-    const size_t new_rtp_len = oldlen + addlen + afterlen + 1;
-    // add one for NUL -------------------------------------^
-    char *const new_rtp = try_malloc(new_rtp_len);
-    if (new_rtp == NULL) {
-      goto theend;
-    }
-    const size_t keep = (size_t)(insp - (const char *)p_rtp);
-    size_t new_rtp_fill = 0;
-    memmove(new_rtp, p_rtp, keep);
-    new_rtp_fill += keep;
+  const size_t oldlen = STRLEN(p_rtp);
+  const size_t addlen = STRLEN(fname) + 1;  // add one for comma
+  const size_t new_rtp_len = oldlen + addlen + afterlen + 1;
+  // add one for NUL -------------------------------------^
+  char *const new_rtp = try_malloc(new_rtp_len);
+  if (new_rtp == NULL) {
+    goto theend;
+  }
+  const size_t keep = (size_t)(insp - (const char *)p_rtp);
+  size_t new_rtp_fill = 0;
+  memmove(new_rtp, p_rtp, keep);
+  new_rtp_fill += keep;
+  new_rtp[new_rtp_fill++] = ',';
+  memmove(new_rtp + new_rtp_fill, fname, addlen);
+  new_rtp_fill += addlen - 1;
+  assert(new_rtp[new_rtp_fill] == NUL || new_rtp[new_rtp_fill] == ',');
+  if (p_rtp[keep] != NUL) {
+    memmove(new_rtp + new_rtp_fill, p_rtp + keep, oldlen - keep + 1);
+    new_rtp_fill += oldlen - keep;
+  }
+  if (afterlen > 0) {
+    assert(new_rtp[new_rtp_fill] == NUL);
     new_rtp[new_rtp_fill++] = ',';
-    memmove(new_rtp + new_rtp_fill, ffname, addlen);
-    new_rtp_fill += addlen - 1;
-    assert(new_rtp[new_rtp_fill] == NUL || new_rtp[new_rtp_fill] == ',');
-    if (p_rtp[keep] != NUL) {
-      memmove(new_rtp + new_rtp_fill, p_rtp + keep, oldlen - keep + 1);
-      new_rtp_fill += oldlen - keep;
-    }
-    if (afterlen > 0) {
-      assert(new_rtp[new_rtp_fill] == NUL);
-      new_rtp[new_rtp_fill++] = ',';
-      memmove(new_rtp + new_rtp_fill, afterdir, afterlen - 1);
-      new_rtp_fill += afterlen - 1;
-    }
-    new_rtp[new_rtp_fill] = NUL;
-    set_option_value("rtp", 0L, new_rtp, 0);
-    xfree(new_rtp);
-    xfree(afterdir);
+    memmove(new_rtp + new_rtp_fill, afterdir, afterlen - 1);
+    new_rtp_fill += afterlen - 1;
+  }
+  new_rtp[new_rtp_fill] = NUL;
+  set_option_value("rtp", 0L, new_rtp, 0);
+  xfree(new_rtp);
+  retval = OK;
+
+theend:
+  xfree(buf);
+  xfree(ffname);
+  xfree(afterdir);
+  return retval;
+}
+
+/// Load scripts in "plugin" and "ftdetect" directories of the package.
+static int load_pack_plugin(char_u *fname)
+{
+  static const char *plugpat = "%s/plugin/**/*.vim";  // NOLINT
+  static const char *ftpat = "%s/ftdetect/*.vim";  // NOLINT
+
+  int retval = FAIL;
+  char *const ffname = fix_fname((char *)fname);
+  size_t len = strlen(ffname) + STRLEN(ftpat);
+  char_u *pat = try_malloc(len + 1);
+  if (pat == NULL) {
+    goto theend;
   }
+  vim_snprintf((char *)pat, len, plugpat, ffname);
+  source_all_matches(pat);
 
-  if (cookie != &APP_ADD_DIR) {
-    static const char *plugpat = "%s/plugin/**/*.vim";  // NOLINT
-    static const char *ftpat = "%s/ftdetect/*.vim";  // NOLINT
+  char_u *cmd = vim_strsave((char_u *)"g:did_load_filetypes");
 
-    size_t len = strlen(ffname) + STRLEN(ftpat);
-    char_u *pat = try_malloc(len + 1);
-    if (pat == NULL) {
-      goto theend;
-    }
-    vim_snprintf((char *)pat, len, plugpat, ffname);
+  // If runtime/filetype.vim wasn't loaded yet, the scripts will be
+  // found when it loads.
+  if (eval_to_number(cmd) > 0) {
+    do_cmdline_cmd("augroup filetypedetect");
+    vim_snprintf((char *)pat, len, ftpat, ffname);
     source_all_matches(pat);
+    do_cmdline_cmd("augroup END");
+  }
+  xfree(cmd);
+  xfree(pat);
+  retval = OK;
+
+theend:
+  xfree(ffname);
+
+  return retval;
+}
 
-    char_u *cmd = vim_strsave((char_u *)"g:did_load_filetypes");
+// used for "cookie" of add_pack_plugin()
+static int APP_ADD_DIR;
+static int APP_LOAD;
+static int APP_BOTH;
 
-    // If runtime/filetype.vim wasn't loaded yet, the scripts will be
-    // found when it loads.
-    if (eval_to_number(cmd) > 0) {
-      do_cmdline_cmd("augroup filetypedetect");
-      vim_snprintf((char *)pat, len, ftpat, ffname);
-      source_all_matches(pat);
-      do_cmdline_cmd("augroup END");
+static void add_pack_plugin(char_u *fname, void *cookie)
+{
+  if (cookie != &APP_LOAD && strstr((char *)p_rtp, (char *)fname) == NULL) {
+    // directory is not yet in 'runtimepath', add it
+    if (add_pack_dir_to_rtp(fname) == FAIL) {
+      return;
     }
-    xfree(cmd);
-    xfree(pat);
   }
 
-theend:
-  xfree(buf);
-  xfree(ffname);
+  if (cookie != &APP_ADD_DIR) {
+    load_pack_plugin(fname);
+  }
 }
 
 /// Add all packages in the "start" directory to 'runtimepath'.
diff --git a/test/functional/legacy/packadd_spec.lua b/test/functional/legacy/packadd_spec.lua
index 7c3d48317b..a73beef0cd 100644
--- a/test/functional/legacy/packadd_spec.lua
+++ b/test/functional/legacy/packadd_spec.lua
@@ -14,6 +14,10 @@ describe('packadd', function()
     clear()
 
     source([=[
+      func Escape(s)
+        return escape(a:s, '\~')
+      endfunc
+
       func SetUp()
         let s:topdir = expand(getcwd() . '/Xdir')
         exe 'set packpath=' . s:topdir
@@ -50,8 +54,8 @@ describe('packadd', function()
         call assert_equal(77, g:plugin_also_works)
         call assert_true(17, g:ftdetect_works)
         call assert_true(len(&rtp) > len(rtp))
-        call assert_true(&rtp =~ (escape(s:plugdir, '\') . '\($\|,\)'))
-        call assert_true(&rtp =~ escape(expand(s:plugdir . '/after$'), '\'))
+        call assert_match(Escape(s:plugdir) . '\($\|,\)', &rtp)
+        call assert_match(Escape(expand(s:plugdir . '/after$')), &rtp)
 
         " Check exception
         call assert_fails("packadd directorynotfound", 'E919:')
@@ -73,7 +77,7 @@ describe('packadd', function()
 
         call assert_equal(24, g:plugin_works)
         call assert_true(len(&rtp) > len(rtp))
-        call assert_true(&rtp =~ (escape(plugdir, '\') . '\($\|,\)'))
+        call assert_match(Escape(plugdir) . '\($\|,\)', &rtp)
       endfunc
 
       func Test_packadd_noload()
@@ -90,7 +94,7 @@ describe('packadd', function()
         packadd! mytest
 
         call assert_true(len(&rtp) > len(rtp))
-        call assert_true(&rtp =~ (escape(s:plugdir, '\') . '\($\|,\)'))
+        call assert_match(Escape(s:plugdir) . '\($\|,\)', &rtp)
         call assert_equal(0, g:plugin_works)
 
         " check the path is not added twice
@@ -122,7 +126,7 @@ describe('packadd', function()
         packadd mytest
 
         " Must have been inserted in the middle, not at the end
-        call assert_true(&rtp =~ escape(expand('/pack/mine/opt/mytest').',', '\'))
+        call assert_match(Escape(expand('/pack/mine/opt/mytest').','), &rtp)
         call assert_equal(44, g:plugin_works)
 
         " No change when doing it again.
@@ -135,6 +139,48 @@ describe('packadd', function()
         exec "silent !" (has('win32') ? "rd /q/s" : "rm") top2_dir
       endfunc
 
+      func Test_packadd_symlink_dir2()
+        let top2_dir = expand(s:topdir . '/Xdir2')
+        let real_dir = expand(s:topdir . '/Xsym/pack')
+        call mkdir(top2_dir, 'p')
+        call mkdir(real_dir, 'p')
+        let &rtp = top2_dir . ',' . top2_dir . '/after'
+        let &packpath = &rtp
+
+        if has('win32')
+          exec "silent! !mklink /d" top2_dir "Xsym"
+        else
+          exec "silent !ln -s ../Xsym/pack"  top2_dir . '/pack'
+        endif
+        let s:plugdir = expand(top2_dir . '/pack/mine/opt/mytest')
+        call mkdir(s:plugdir . '/plugin', 'p')
+
+        exe 'split ' . s:plugdir . '/plugin/test.vim'
+        call setline(1, 'let g:plugin_works = 48')
+        wq
+        let g:plugin_works = 0
+
+        packadd mytest
+
+        " Must have been inserted in the middle, not at the end
+        call assert_match(Escape(expand('/Xdir2/pack/mine/opt/mytest').','), &rtp)
+        call assert_equal(48, g:plugin_works)
+
+        " No change when doing it again.
+        let rtp_before = &rtp
+        packadd mytest
+        call assert_equal(rtp_before, &rtp)
+
+        set rtp&
+        let rtp = &rtp
+        if has('win32')
+          exec "silent !rd /q/s" top2_dir
+        else
+          exec "silent !rm" top2_dir . '/pack'
+          exec "silent !rmdir" top2_dir
+        endif
+      endfunc
+
       func Test_packloadall()
         " plugin foo with an autoload directory
         let fooplugindir = &packpath . '/pack/mine/start/foo/plugin'
@@ -190,9 +236,9 @@ describe('packadd', function()
         helptags ALL
 
         let tags1 = readfile(docdir1 . '/tags')
-        call assert_true(tags1[0] =~ 'look-here')
+        call assert_match('look-here', tags1[0])
         let tags2 = readfile(docdir2 . '/tags')
-        call assert_true(tags2[0] =~ 'look-away')
+        call assert_match('look-away', tags2[0])
       endfunc
 
       func Test_colorscheme()