patch 8.2.2760: Vim9: no error for changing a for loop variable

Problem:    Vim9: no error for changing a for loop variable.
Solution:   Make the loop variable read-only. (issue #8102)

diff --git a/src/eval.c b/src/eval.c
index 2e2ca23b6974641a974c29484cff17b25c0c438c..99768ee280cda0c5a7ddb6be1e23ceca9d8b537d 100644 (file)
--- a/src/eval.c
+++ b/src/eval.c
@@ -1351,7 +1351,8 @@ set_var_lval(
        {
            typval_T tv;
 
-           if (flags & (ASSIGN_CONST | ASSIGN_FINAL))
+           if ((flags & (ASSIGN_CONST | ASSIGN_FINAL))
+                                            && (flags & ASSIGN_FOR_LOOP) == 0)
            {
                emsg(_(e_cannot_mod));
                *endp = cc;
@@ -1390,7 +1391,8 @@ set_var_lval(
        listitem_T *ll_li = lp->ll_li;
        int         ll_n1 = lp->ll_n1;
 
-       if (flags & (ASSIGN_CONST | ASSIGN_FINAL))
+       if ((flags & (ASSIGN_CONST | ASSIGN_FINAL))
+                                            && (flags & ASSIGN_FOR_LOOP) == 0)
        {
            emsg(_("E996: Cannot lock a range"));
            return;
@@ -1449,7 +1451,8 @@ set_var_lval(
        /*
         * Assign to a List or Dictionary item.
         */
-       if (flags & (ASSIGN_CONST | ASSIGN_FINAL))
+       if ((flags & (ASSIGN_CONST | ASSIGN_FINAL))
+                                            && (flags & ASSIGN_FOR_LOOP) == 0)
        {
            emsg(_("E996: Cannot lock a list or dict"));
            return;
@@ -1775,7 +1778,9 @@ next_for_item(void *fi_void, char_u *arg)
 {
     forinfo_T  *fi = (forinfo_T *)fi_void;
     int                result;
-    int                flag = in_vim9script() ? ASSIGN_DECL : 0;
+    int                flag = ASSIGN_FOR_LOOP | (in_vim9script()
+                        ? (ASSIGN_FINAL | ASSIGN_DECL | ASSIGN_NO_MEMBER_TYPE)
+                        : 0);
     listitem_T *item;
 
     if (fi->fi_blob != NULL)

diff --git a/src/evalvars.c b/src/evalvars.c
index b8a4352f8afd7c0e01636b109c559deee848f10a..eb9ad6da1613d5eea1c83d8cc3e9fdeea9dd345e 100644 (file)
--- a/src/evalvars.c
+++ b/src/evalvars.c
@@ -1315,7 +1315,8 @@ ex_let_one(
     // ":let $VAR = expr": Set environment variable.
     if (*arg == '$')
     {
-       if (flags & (ASSIGN_CONST | ASSIGN_FINAL))
+       if ((flags & (ASSIGN_CONST | ASSIGN_FINAL))
+                                            && (flags & ASSIGN_FOR_LOOP) == 0)
        {
            emsg(_("E996: Cannot lock an environment variable"));
            return NULL;
@@ -1365,9 +1366,11 @@ ex_let_one(
     // ":let &option = expr": Set option value.
     // ":let &l:option = expr": Set local option value.
     // ":let &g:option = expr": Set global option value.
+    // ":for &ts in range(8)": Set option value for for loop
     else if (*arg == '&')
     {
-       if (flags & (ASSIGN_CONST | ASSIGN_FINAL))
+       if ((flags & (ASSIGN_CONST | ASSIGN_FINAL))
+                                            && (flags & ASSIGN_FOR_LOOP) == 0)
        {
            emsg(_(e_const_option));
            return NULL;
@@ -1466,7 +1469,8 @@ ex_let_one(
     // ":let @r = expr": Set register contents.
     else if (*arg == '@')
     {
-       if (flags & (ASSIGN_CONST | ASSIGN_FINAL))
+       if ((flags & (ASSIGN_CONST | ASSIGN_FINAL))
+                                            && (flags & ASSIGN_FOR_LOOP) == 0)
        {
            emsg(_("E996: Cannot lock a register"));
            return NULL;
@@ -3158,7 +3162,7 @@ set_var_const(
     type_T     *type,
     typval_T   *tv_arg,
     int                copy,       // make copy of value in "tv"
-    int                flags,      // ASSIGN_CONST, ASSIGN_FINAL, etc.
+    int                flags_arg,  // ASSIGN_CONST, ASSIGN_FINAL, etc.
     int                var_idx)    // index for ":let [a, b] = list"
 {
     typval_T   *tv = tv_arg;
@@ -3169,6 +3173,7 @@ set_var_const(
     int                is_script_local;
     int                vim9script = in_vim9script();
     int                var_in_vim9script;
+    int                flags = flags_arg;
 
     ht = find_var_ht(name, &varname);
     if (ht == NULL || *varname == NUL)
@@ -3187,6 +3192,11 @@ set_var_const(
        vim9_declare_error(name);
        goto failed;
     }
+    if ((flags & ASSIGN_FOR_LOOP) && name[1] == ':'
+                             && vim_strchr((char_u *)"gwbt", name[0]) != NULL)
+       // Do not make g:var, w:var, b:var or t:var final.
+       flags &= ~ASSIGN_FINAL;
+
     var_in_vim9script = is_script_local && current_script_is_vim9();
     if (var_in_vim9script && name[0] == '_' && name[1] == NUL)
     {
@@ -3220,7 +3230,8 @@ set_var_const(
        // Item already exists.  Allowed to replace when reloading.
        if ((di->di_flags & DI_FLAGS_RELOAD) == 0)
        {
-           if (flags & (ASSIGN_CONST | ASSIGN_FINAL))
+           if ((flags & (ASSIGN_CONST | ASSIGN_FINAL))
+                                            && (flags & ASSIGN_FOR_LOOP) == 0)
            {
                emsg(_(e_cannot_mod));
                goto failed;
@@ -3255,7 +3266,8 @@ set_var_const(
            // A Vim9 script-local variable is also present in sn_all_vars and
            // sn_var_vals.  It may set "type" from "tv".
            if (var_in_vim9script)
-               update_vim9_script_var(FALSE, di, flags, tv, &type);
+               update_vim9_script_var(FALSE, di, flags, tv, &type,
+                                        (flags & ASSIGN_NO_MEMBER_TYPE) == 0);
        }
 
        // existing variable, need to clear the value
@@ -3353,7 +3365,8 @@ set_var_const(
        // A Vim9 script-local variable is also added to sn_all_vars and
        // sn_var_vals. It may set "type" from "tv".
        if (var_in_vim9script)
-           update_vim9_script_var(TRUE, di, flags, tv, &type);
+           update_vim9_script_var(TRUE, di, flags, tv, &type,
+                                        (flags & ASSIGN_NO_MEMBER_TYPE) == 0);
     }
 
     if (copy || tv->v_type == VAR_NUMBER || tv->v_type == VAR_FLOAT)

diff --git a/src/testdir/test_vim9_script.vim b/src/testdir/test_vim9_script.vim
index db1707ace60f011931f04acdf798a397daa18577..af7e5fdbb6122017e25812c8058ec3f3da99e001 100644 (file)
--- a/src/testdir/test_vim9_script.vim
+++ b/src/testdir/test_vim9_script.vim
@@ -2393,6 +2393,14 @@ def Test_for_loop_fails()
   g:adict = {a: 1}
   CheckDefExecFailure(['for i in g:adict', 'echo 3', 'endfor'], 'E1177: For loop on dict not supported')
   unlet g:adict
+
+  var lines =<< trim END
+      var d: list<dict<any>> = [{a: 0}]
+      for e in d
+        e = {a: 0, b: ''}
+      endfor
+  END
+  CheckDefAndScriptFailure2(lines, 'E1018:', 'E46:', 3)
 enddef
 
 def Test_for_loop_script_var()

diff --git a/src/version.c b/src/version.c
index fdb8d0a9b5c82d9981ab93cf2dd591304b5a17fc..4861ba1a9fdf5bda5fbab13f8b1d0102528e5419 100644 (file)
--- a/src/version.c
+++ b/src/version.c
@@ -750,6 +750,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    2760,
 /**/
     2759,
 /**/

diff --git a/src/vim.h b/src/vim.h
index baa3526d0feddedb32b63b2b3eab005eedb7343a..4c9e095a10d370e5877be9e0ecf7dc0d01a673a2 100644 (file)
--- a/src/vim.h
+++ b/src/vim.h
@@ -2158,6 +2158,7 @@ typedef enum {
 #define ASSIGN_DECL    0x08  // may declare variable if it does not exist
 #define ASSIGN_UNPACK  0x10  // using [a, b] = list
 #define ASSIGN_NO_MEMBER_TYPE 0x20 // use "any" for list and dict member type
+#define ASSIGN_FOR_LOOP 0x40 // assigning to loop variable
 
 #include "ex_cmds.h"       // Ex command defines
 #include "spell.h"         // spell checking stuff

diff --git a/src/vim9compile.c b/src/vim9compile.c
index bcba1e3224696d7c7faf09414d2599c3fb7d029e..4a55f1973baaf785a565516f7caa76a5ec9517dd 100644 (file)
--- a/src/vim9compile.c
+++ b/src/vim9compile.c
@@ -7590,7 +7590,7 @@ compile_for(char_u *arg_start, cctx_T *cctx)
 
            // Reserve a variable to store "var".
            // TODO: check for type
-           var_lvar = reserve_local(cctx, arg, varlen, FALSE, &t_any);
+           var_lvar = reserve_local(cctx, arg, varlen, TRUE, &t_any);
            if (var_lvar == NULL)
                // out of memory or used as an argument
                goto failed;