Merge pull request #20826 from zeertzjq/vim-8.2.4206

vim-patch:8.2.{4070,4206,4207}

src/nvim/eval.c

@@ -65,6 +65,7 @@ static char *e_nowhitespace
   = N_("E274: No white space allowed before parenthesis");
 static char *e_write2 = N_("E80: Error while writing: %s");
 static char *e_string_list_or_blob_required = N_("E1098: String, List or Blob required");
+static char e_expression_too_recursive_str[] = N_("E1169: Expression too recursive: %s");
 
 static char * const namespace_char = "abglstvw";
 
@@ -2911,6 +2912,7 @@ static int eval7(char **arg, typval_T *rettv, int evaluate, int want_string)
   const char *start_leader, *end_leader;
   int ret = OK;
   char *alias;
+  static int recurse = 0;
 
   // Initialise variable so that tv_clear() can't mistake this for a
   // string and free a string that isn't there.
@@ -2923,6 +2925,20 @@ static int eval7(char **arg, typval_T *rettv, int evaluate, int want_string)
   }
   end_leader = *arg;
 
+  // Limit recursion to 1000 levels.  At least at 10000 we run out of stack
+  // and crash.  With MSVC the stack is smaller.
+  if (recurse ==
+#ifdef _MSC_VER
+      300
+#else
+      1000
+#endif
+      ) {
+    semsg(_(e_expression_too_recursive_str), *arg);
+    return FAIL;
+  }
+  recurse++;
+
   switch (**arg) {
   // Number constant.
   case '0':
@@ -3127,6 +3143,8 @@ static int eval7(char **arg, typval_T *rettv, int evaluate, int want_string)
   if (ret == OK && evaluate && end_leader > start_leader) {
     ret = eval7_leader(rettv, (char *)start_leader, &end_leader);
   }
+
+  recurse--;
   return ret;
 }
 

src/nvim/eval/funcs.c

@@ -5921,7 +5921,7 @@ static void f_readfile(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
     for (p = buf, start = buf;
          p < buf + readlen || (readlen <= 0 && (prevlen > 0 || binary));
          p++) {
-      if (*p == '\n' || readlen <= 0) {
+      if (readlen <= 0 || *p == '\n') {
         char *s  = NULL;
         size_t len = (size_t)(p - start);
 

src/nvim/testdir/test_eval_stuff.vim

@@ -120,6 +120,13 @@ func Test_readfile_binary()
   call delete('XReadfile_bin')
 endfunc
 
+func Test_readfile_binary_empty()
+  call writefile([], 'Xempty-file')
+  " This used to compare uninitialized memory in Vim <= 8.2.4065
+  call assert_equal([''], readfile('Xempty-file', 'b'))
+  call delete('Xempty-file')
+endfunc
+
 func Test_readfile_bom()
   call writefile(["\ufeffFOO", "FOO\ufeffBAR"], 'XReadfile_bom')
   call assert_equal(['FOO', 'FOOBAR'], readfile('XReadfile_bom'))
@@ -360,6 +367,11 @@ func Test_curly_assignment()
   unlet g:gvar
 endfunc
 
+func Test_deep_recursion()
+  " this was running out of stack
+  call assert_fails("exe 'if ' .. repeat('(', 1002)", 'E1169: Expression too recursive: ((')
+endfunc
+
 " K_SPECIAL in the modified character used be escaped, which causes
 " double-escaping with feedkeys() or as the return value of an <expr> mapping,
 " and doesn't match what getchar() returns,