vim-patch:9.1.0811: :find expansion does not consider 'findexpr'

Problem:  :find expansion does not consider 'findexpr'
Solution: Support expanding :find command argument using 'findexpr'
          (Yegappan Lakshmanan)

closes: vim/vim#15929

https://github.com/vim/vim/commit/2f6efaccfd5c4e7df1f54ed0f41f329abbe05f60

Co-authored-by: Yegappan Lakshmanan <yegappan@yahoo.com>

6 files changed, 105 insertions, 35 deletions

diff --git a/runtime/doc/options.txt b/runtime/doc/options.txt
index 17b2d22173..441f180177 100644
--- a/runtime/doc/options.txt
+++ b/runtime/doc/options.txt
@@ -2598,7 +2598,7 @@ A jump table for the options with a short description can be found at |Q_op|.
 	  eob		EndOfBuffer		|hl-EndOfBuffer|
 	  lastline	NonText			|hl-NonText|
 
-						*'findexpr'* *'fexpr'*
+					*'findexpr'* *'fexpr'* *E1514*
 'findexpr' 'fexpr'	string	(default "")
 			global or local to buffer |global-local|
 	Expression that is evaluated to obtain the filename(s) for the |:find|
diff --git a/src/nvim/cmdexpand.c b/src/nvim/cmdexpand.c
index 549ed826bc..5b7017481e 100644
--- a/src/nvim/cmdexpand.c
+++ b/src/nvim/cmdexpand.c
@@ -2497,21 +2497,25 @@ static int expand_files_and_dirs(expand_T *xp, char *pat, char ***matches, int *
     }
   }
 
-  if (xp->xp_context == EXPAND_FILES) {
-    flags |= EW_FILE;
-  } else if (xp->xp_context == EXPAND_FILES_IN_PATH) {
-    flags |= (EW_FILE | EW_PATH);
-  } else if (xp->xp_context == EXPAND_DIRS_IN_CDPATH) {
-    flags = (flags | EW_DIR | EW_CDPATH) & ~EW_FILE;
+  int ret = FAIL;
+  if (xp->xp_context == EXPAND_FILES_IN_PATH && *get_findexpr() != NUL) {
+    ret = expand_findexpr(pat, matches, numMatches);
   } else {
-    flags = (flags | EW_DIR) & ~EW_FILE;
-  }
-  if (options & WILD_ICASE) {
-    flags |= EW_ICASE;
+    if (xp->xp_context == EXPAND_FILES) {
+      flags |= EW_FILE;
+    } else if (xp->xp_context == EXPAND_FILES_IN_PATH) {
+      flags |= (EW_FILE | EW_PATH);
+    } else if (xp->xp_context == EXPAND_DIRS_IN_CDPATH) {
+      flags = (flags | EW_DIR | EW_CDPATH) & ~EW_FILE;
+    } else {
+      flags = (flags | EW_DIR) & ~EW_FILE;
+    }
+    if (options & WILD_ICASE) {
+      flags |= EW_ICASE;
+    }
+    // Expand wildcards, supporting %:h and the like.
+    ret = expand_wildcards_eval(&pat, numMatches, matches, flags);
   }
-
-  // Expand wildcards, supporting %:h and the like.
-  int ret = expand_wildcards_eval(&pat, numMatches, matches, flags);
   if (free_pat) {
     xfree(pat);
   }
diff --git a/src/nvim/errors.h b/src/nvim/errors.h
index bea56541a2..6bbec84ff9 100644
--- a/src/nvim/errors.h
+++ b/src/nvim/errors.h
@@ -186,6 +186,7 @@ INIT(= N_("E5767: Cannot use :undo! to redo or move to a different undo branch")
 
 EXTERN const char e_winfixbuf_cannot_go_to_buffer[]
 INIT(= N_("E1513: Cannot switch buffer. 'winfixbuf' is enabled"));
+EXTERN const char e_invalid_return_type_from_findexpr[] INIT( = N_("E1514: findexpr did not return a List type"));
 
 EXTERN const char e_trustfile[] INIT(= N_("E5570: Cannot update trust file: %s"));
 
diff --git a/src/nvim/ex_docmd.c b/src/nvim/ex_docmd.c
index 5c61399003..f89c992cf9 100644
--- a/src/nvim/ex_docmd.c
+++ b/src/nvim/ex_docmd.c
@@ -5167,28 +5167,17 @@ static void ex_wrongmodifier(exarg_T *eap)
 
 /// Evaluate the 'findexpr' expression and return the result.  When evaluating
 /// the expression, v:fname is set to the ":find" command argument.
-static list_T *eval_findexpr(const char *ptr, size_t len)
+static list_T *eval_findexpr(const char *ptr)
 {
   const sctx_T saved_sctx = current_sctx;
-  bool use_sandbox = false;
 
-  char *findexpr;
-  if (*curbuf->b_p_fexpr == NUL) {
-    use_sandbox = was_set_insecurely(curwin, kOptFindexpr, OPT_GLOBAL);
-    findexpr = p_fexpr;
-  } else {
-    use_sandbox = was_set_insecurely(curwin, kOptFindexpr, OPT_LOCAL);
-    findexpr = curbuf->b_p_fexpr;
-  }
+  char *findexpr = get_findexpr();
 
-  set_vim_var_string(VV_FNAME, ptr, (ptrdiff_t)len);
+  set_vim_var_string(VV_FNAME, ptr, -1);
   current_sctx = curbuf->b_p_script_ctx[BV_FEXPR].script_ctx;
 
   char *arg = skipwhite(findexpr);
 
-  if (use_sandbox) {
-    sandbox++;
-  }
   textlock++;
 
   // Evaluate the expression.  If the expression is "FuncName()" call the
@@ -5200,12 +5189,11 @@ static list_T *eval_findexpr(const char *ptr, size_t len)
   } else {
     if (tv.v_type == VAR_LIST) {
       retlist = tv_list_copy(NULL, tv.vval.v_list, true, get_copyID());
+    } else {
+      emsg(_(e_invalid_return_type_from_findexpr));
     }
     tv_clear(&tv);
   }
-  if (use_sandbox) {
-    sandbox--;
-  }
   textlock--;
   clear_evalarg(&EVALARG_EVALUATE, NULL);
 
@@ -5215,6 +5203,52 @@ static list_T *eval_findexpr(const char *ptr, size_t len)
   return retlist;
 }
 
+/// Find file names matching "pat" using 'findexpr' and return it in "files".
+/// Used for expanding the :find, :sfind and :tabfind command argument.
+/// Returns OK on success and FAIL otherwise.
+int expand_findexpr(const char *pat, char ***files, int *numMatches)
+{
+  *numMatches = 0;
+  *files = NULL;
+
+  // File name expansion uses wildchars.  But the 'findexpr' expression
+  // expects a regular expression argument.  So convert wildchars in the
+  // argument to regular expression patterns.
+  char *regpat = file_pat_to_reg_pat(pat, NULL, NULL, false);
+  if (regpat == NULL) {
+    return FAIL;
+  }
+
+  list_T *l = eval_findexpr(regpat);
+
+  xfree(regpat);
+
+  if (l == NULL) {
+    return FAIL;
+  }
+
+  int len = tv_list_len(l);
+  if (len == 0) {  // empty List
+    return FAIL;
+  }
+
+  *files = xmalloc(sizeof(char *) * (size_t)len);
+
+  // Copy all the List items
+  int idx = 0;
+  TV_LIST_ITER_CONST(l, li, {
+    if (TV_LIST_ITEM_TV(li)->v_type == VAR_STRING) {
+      (*files)[idx] = xstrdup(TV_LIST_ITEM_TV(li)->vval.v_string);
+      idx++;
+    }
+  });
+
+  *numMatches = idx;
+  tv_list_free(l);
+
+  return OK;
+}
+
 /// Use 'findexpr' to find file 'findarg'.  The 'count' argument is used to find
 /// the n'th matching file.
 static char *findexpr_find_file(char *findarg, size_t findarg_len, int count)
@@ -5224,7 +5258,7 @@ static char *findexpr_find_file(char *findarg, size_t findarg_len, int count)
   const char cc = findarg[findarg_len];
   findarg[findarg_len] = NUL;
 
-  list_T *fname_list = eval_findexpr(findarg, findarg_len);
+  list_T *fname_list = eval_findexpr(findarg);
   int fname_count = tv_list_len(fname_list);
 
   if (fname_count == 0) {
diff --git a/src/nvim/options.lua b/src/nvim/options.lua
index 65401fb3a9..2e037d80d3 100644
--- a/src/nvim/options.lua
+++ b/src/nvim/options.lua
@@ -2955,6 +2955,7 @@ return {
       scope = { 'global', 'buffer' },
       secure = true,
       short_desc = N_('expression used for :find'),
+      tags = { 'E1514' },
       type = 'string',
       varname = 'p_fexpr',
     },
diff --git a/test/old/testdir/test_findfile.vim b/test/old/testdir/test_findfile.vim
index baf33898fe..8e25975b53 100644
--- a/test/old/testdir/test_findfile.vim
+++ b/test/old/testdir/test_findfile.vim
@@ -299,7 +299,6 @@ func Test_findexpr()
   " basic tests
   func FindExpr1()
     let fnames = ['Xfindexpr1.c', 'Xfindexpr2.c', 'Xfindexpr3.c']
-    "return fnames->copy()->filter('v:val =~? v:fname')->join("\n")
     return fnames->copy()->filter('v:val =~? v:fname')
   endfunc
 
@@ -358,8 +357,8 @@ func Test_findexpr()
   set findexpr=FindExpr2()
   call assert_fails('find Xfindexpr1.c', 'find error')
 
-  " Try using a null string as the expression
-  set findexpr=v:_null_string
+  " Try using a null List as the expression
+  set findexpr=v:_null_list
   call assert_fails('find Xfindexpr1.c', 'E345: Can''t find file "Xfindexpr1.c" in path')
 
   " Try to create a new window from the find expression
@@ -378,6 +377,10 @@ func Test_findexpr()
   set findexpr=FindExpr4()
   call assert_fails('find Xfindexpr1.c', 'E565: Not allowed to change text or change window')
 
+  " Expression returning a string
+  set findexpr='abc'
+  call assert_fails('find Xfindexpr1.c', 'E1514: findexpr did not return a List type')
+
   set findexpr&
   delfunc! FindExpr1
   delfunc! FindExpr2
@@ -454,4 +457,31 @@ func Test_findexpr_scriptlocal_func()
   delfunc s:FindExprScript
 endfunc
 
+" Test for expanding the argument to the :find command using 'findexpr'
+func Test_findexpr_expand_arg()
+  func FindExpr1()
+    let fnames = ['Xfindexpr1.c', 'Xfindexpr2.c', 'Xfindexpr3.c']
+    return fnames->copy()->filter('v:val =~? v:fname')
+  endfunc
+  set findexpr=FindExpr1()
+
+  call feedkeys(":find \<Tab>\<C-B>\"\<CR>", "xt")
+  call assert_equal('"find Xfindexpr1.c', @:)
+
+  call feedkeys(":find Xfind\<Tab>\<Tab>\<C-B>\"\<CR>", "xt")
+  call assert_equal('"find Xfindexpr2.c', @:)
+
+  call feedkeys(":find *3*\<Tab>\<C-B>\"\<CR>", "xt")
+  call assert_equal('"find Xfindexpr3.c', @:)
+
+  call feedkeys(":find Xfind\<C-A>\<C-B>\"\<CR>", "xt")
+  call assert_equal('"find Xfindexpr1.c Xfindexpr2.c Xfindexpr3.c', @:)
+
+  call feedkeys(":find abc\<Tab>\<C-B>\"\<CR>", "xt")
+  call assert_equal('"find abc', @:)
+
+  set findexpr&
+  delfunc! FindExpr1
+endfunc
+
 " vim: shiftwidth=2 sts=2 expandtab