vim-patch:8.0.1239: cannot use a lambda for the skip argument to searchpair()

Problem:    Cannot use a lambda for the skip argument to searchpair().
Solution:   Evaluate a partial, funcref and lambda. (LemonBoy, closes vim/vim#1454,
            closes vim/vim#2265)
48570488f1

src/nvim/eval.c

@@ -955,6 +955,63 @@ eval_to_bool(
   return retval;
 }
 
+static int eval_expr_typval(const typval_T *expr, typval_T *argv,
+                            int argc, typval_T *rettv)
+{
+  int dummy;
+
+  if (expr->v_type == VAR_FUNC) {
+    const char_u *const s = expr->vval.v_string;
+    if (s == NULL || *s == NUL) {
+      return FAIL;
+    }
+    if (call_func(s, (int)STRLEN(s), rettv, argc, argv, NULL,
+                  0L, 0L, &dummy, true, NULL, NULL) == FAIL) {
+      return FAIL;
+    }
+  } else if (expr->v_type == VAR_PARTIAL) {
+    partial_T *const partial = expr->vval.v_partial;
+    const char_u *const s = partial_name(partial);
+    if (s == NULL || *s == NUL) {
+      return FAIL;
+    }
+    if (call_func(s, (int)STRLEN(s), rettv, argc, argv, NULL,
+                  0L, 0L, &dummy, true, partial, NULL) == FAIL) {
+      return FAIL;
+    }
+  } else {
+    char buf[NUMBUFLEN];
+    char_u *s = (char_u *)tv_get_string_buf_chk(expr, buf);
+    if (s == NULL) {
+      return FAIL;
+    }
+    s = skipwhite(s);
+    if (eval1(&s, rettv, true) == FAIL) {
+      return FAIL;
+    }
+    if (*s != NUL) {  // check for trailing chars after expr
+      emsgf(_(e_invexpr2), s);
+      return FAIL;
+    }
+  }
+  return OK;
+}
+
+/// Like eval_to_bool() but using a typval_T instead of a string.
+/// Works for string, funcref and partial.
+static bool eval_expr_to_bool(const typval_T *expr, bool *error)
+{
+  typval_T rettv;
+
+  if (eval_expr_typval(expr, NULL, 0, &rettv) == FAIL) {
+    *error = true;
+    return false;
+  }
+  const bool res = (tv_get_number_chk(&rettv, error) != 0);
+  tv_clear(&rettv);
+  return res;
+}
+
 /// Top level evaluation function, returning a string
 ///
 /// @param[in]  arg  String to evaluate.
@@ -8864,41 +8921,13 @@ static int filter_map_one(typval_T *tv, typval_T *expr, int map, int *remp)
   typval_T rettv;
   typval_T argv[3];
   int retval = FAIL;
-  int dummy;
 
   tv_copy(tv, &vimvars[VV_VAL].vv_tv);
   argv[0] = vimvars[VV_KEY].vv_tv;
   argv[1] = vimvars[VV_VAL].vv_tv;
-  if (expr->v_type == VAR_FUNC) {
-    const char_u *const s = expr->vval.v_string;
-    if (call_func(s, (int)STRLEN(s), &rettv, 2, argv, NULL,
-                  0L, 0L, &dummy, true, NULL, NULL) == FAIL) {
+  if (eval_expr_typval(expr, argv, 2, &rettv) == FAIL) {
     goto theend;
   }
-  } else if (expr->v_type == VAR_PARTIAL) {
-    partial_T *partial = expr->vval.v_partial;
-
-    const char_u *const s = partial_name(partial);
-    if (call_func(s, (int)STRLEN(s), &rettv, 2, argv, NULL,
-                  0L, 0L, &dummy, true, partial, NULL) == FAIL) {
-      goto theend;
-    }
-  } else {
-    char buf[NUMBUFLEN];
-    const char *s = tv_get_string_buf_chk(expr, buf);
-    if (s == NULL) {
-      goto theend;
-    }
-    s = (const char *)skipwhite((const char_u *)s);
-    if (eval1((char_u **)&s, &rettv, true) == FAIL) {
-      goto theend;
-    }
-
-    if (*s != NUL) {  // check for trailing chars after expr
-      emsgf(_(e_invexpr2), s);
-      goto theend;
-    }
-  }
   if (map) {
     // map(): replace the list item value.
     tv_clear(tv);
@@ -14501,7 +14530,6 @@ static int searchpair_cmn(typval_T *argvars, pos_T *match_pos)
   // Get the three pattern arguments: start, middle, end.
   char nbuf1[NUMBUFLEN];
   char nbuf2[NUMBUFLEN];
-  char nbuf3[NUMBUFLEN];
   const char *spat = tv_get_string_chk(&argvars[0]);
   const char *mpat = tv_get_string_buf_chk(&argvars[1], nbuf1);
   const char *epat = tv_get_string_buf_chk(&argvars[2], nbuf2);
@@ -14529,13 +14557,15 @@ static int searchpair_cmn(typval_T *argvars, pos_T *match_pos)
   }
 
   // Optional fifth argument: skip expression.
-  const char *skip;
+  const typval_T *skip;
   if (argvars[3].v_type == VAR_UNKNOWN
       || argvars[4].v_type == VAR_UNKNOWN) {
-    skip = "";
+    skip = NULL;
   } else {
-    skip = tv_get_string_buf_chk(&argvars[4], nbuf3);
-    if (skip == NULL) {
+    skip = &argvars[4];
+    if (skip->v_type != VAR_FUNC
+        && skip->v_type != VAR_PARTIAL
+        && skip->v_type != VAR_STRING) {
       goto theend;  // Type error.
     }
     if (argvars[5].v_type != VAR_UNKNOWN) {
@@ -14553,7 +14583,7 @@ static int searchpair_cmn(typval_T *argvars, pos_T *match_pos)
   }
 
   retval = do_searchpair(
-      (char_u *)spat, (char_u *)mpat, (char_u *)epat, dir, (char_u *)skip,
+      (char_u *)spat, (char_u *)mpat, (char_u *)epat, dir, skip,
       flags, match_pos, lnum_stop, time_limit);
 
 theend:
@@ -14601,7 +14631,7 @@ do_searchpair(
     char_u *mpat,          // middle pattern
     char_u *epat,          // end pattern
     int dir,               // BACKWARD or FORWARD
-    char_u *skip,          // skip expression
+    const typval_T *skip,  // skip expression
     int flags,             // SP_SETPCMARK and other SP_ values
     pos_T *match_pos,
     linenr_T lnum_stop,    // stop at this line if not zero
@@ -14619,6 +14649,7 @@ do_searchpair(
   int n;
   int r;
   int nest = 1;
+  bool use_skip = false;
   int options = SEARCH_KEEP;
   proftime_T tm;
   size_t pat2_len;
@@ -14648,6 +14679,13 @@ do_searchpair(
     options |= SEARCH_START;
   }
 
+  if (skip != NULL) {
+    // Empty string means to not use the skip expression.
+    if (skip->v_type == VAR_STRING || skip->v_type == VAR_FUNC) {
+      use_skip = skip->vval.v_string != NULL && *skip->vval.v_string != NUL;
+    }
+  }
+
   save_cursor = curwin->w_cursor;
   pos = curwin->w_cursor;
   clearpos(&firstpos);
@@ -14678,11 +14716,11 @@ do_searchpair(
     options &= ~SEARCH_START;
 
     /* If the skip pattern matches, ignore this match. */
-    if (*skip != NUL) {
+    if (use_skip) {
       save_pos = curwin->w_cursor;
       curwin->w_cursor = pos;
-      bool err;
-      r = eval_to_bool(skip, &err, NULL, false);
+      bool err = false;
+      r = eval_expr_to_bool(skip, &err);
       curwin->w_cursor = save_pos;
       if (err) {
         /* Evaluating {skip} caused an error, break here. */

src/nvim/search.c

@@ -3432,7 +3432,7 @@ again:
     if (do_searchpair((char_u *)
             "<[^ \t>/!]\\+\\%(\\_s\\_[^>]\\{-}[^/]>\\|$\\|\\_s\\=>\\)",
             (char_u *)"",
-            (char_u *)"</[^>]*>", BACKWARD, (char_u *)"", 0,
+            (char_u *)"</[^>]*>", BACKWARD, NULL, 0,
             NULL, (linenr_T)0, 0L) <= 0) {
       curwin->w_cursor = old_pos;
       goto theend;
@@ -3459,7 +3459,7 @@ again:
   sprintf((char *)spat, "<%.*s\\>\\%%(\\s\\_[^>]\\{-}[^/]>\\|>\\)\\c", len, p);
   sprintf((char *)epat, "</%.*s>\\c", len, p);
 
-  r = do_searchpair(spat, (char_u *)"", epat, FORWARD, (char_u *)"",
+  r = do_searchpair(spat, (char_u *)"", epat, FORWARD, NULL,
       0, NULL, (linenr_T)0, 0L);
 
   xfree(spat);

src/nvim/testdir/test_search.vim

@@ -298,6 +298,25 @@ func Test_searchpair()
   q!
 endfunc
 
+func Test_searchpair_skip()
+    func Zero()
+	return 0
+    endfunc
+    func Partial(x)
+	return a:x
+    endfunc
+    new
+    call setline(1, ['{', 'foo', 'foo', 'foo', '}'])
+    3 | call assert_equal(1, searchpair('{', '', '}', 'bWn', ''))
+    3 | call assert_equal(1, searchpair('{', '', '}', 'bWn', '0'))
+    3 | call assert_equal(1, searchpair('{', '', '}', 'bWn', {-> 0}))
+    3 | call assert_equal(1, searchpair('{', '', '}', 'bWn', function('Zero')))
+    3 | call assert_equal(1, searchpair('{', '', '}', 'bWn', function('Partial', [0])))
+    " invalid argument
+    3 | call assert_equal(0, searchpair('{', '', '}', 'bWn', 0))
+    bw!
+endfunc
+
 func Test_searchc()
   " These commands used to cause memory overflow in searchc().
   new