vim-patch:8.2.2765: Vim9: not all blob operations work

Problem:    Vim9: not all blob operations work.
Solution:   Run more tests also with Vim9 script and :def functions.  Fix what
            doesn't work.

0e3ff19196

Co-authored-by: Bram Moolenaar <Bram@vim.org>

src/nvim/eval.c

@@ -1498,21 +1498,14 @@ char *get_lval(char *const name, typval_T *const rettv, lval_T *const lp, const
       tv_clear(&var1);
 
       const int bloblen = tv_blob_len(lp->ll_tv->vval.v_blob);
-      if (lp->ll_n1 < 0 || lp->ll_n1 > bloblen
+      if (tv_blob_check_index(bloblen, lp->ll_n1, lp->ll_range, quiet) == FAIL) {
-          || (lp->ll_range && lp->ll_n1 == bloblen)) {
-        if (!quiet) {
-          semsg(_(e_blobidx), (int64_t)lp->ll_n1);
-        }
         tv_clear(&var2);
         return NULL;
       }
       if (lp->ll_range && !lp->ll_empty2) {
         lp->ll_n2 = (long)tv_get_number(&var2);
         tv_clear(&var2);
-        if (lp->ll_n2 < 0 || lp->ll_n2 >= bloblen || lp->ll_n2 < lp->ll_n1) {
+        if (tv_blob_check_range(bloblen, lp->ll_n1, lp->ll_n2, quiet) == FAIL) {
-          if (!quiet) {
-            semsg(_(e_blobidx), (int64_t)lp->ll_n2);
-          }
           return NULL;
         }
       }

src/nvim/eval/typval.c

@@ -2710,6 +2710,30 @@ bool tv_blob_equal(const blob_T *const b1, const blob_T *const b2)
   return true;
 }
 
+/// Check if "n1" is a valid index for a blob with length "bloblen".
+int tv_blob_check_index(int bloblen, varnumber_T n1, int is_range, bool quiet)
+{
+  if (n1 < 0 || n1 > bloblen) {
+    if (!quiet) {
+      semsg(_(e_blobidx), n1);
+    }
+    return FAIL;
+  }
+  return OK;
+}
+
+/// Check if "n1"-"n2" is a valid range for a blob with length "bloblen".
+int tv_blob_check_range(int bloblen, varnumber_T n1, varnumber_T n2, bool quiet)
+{
+  if (n2 < 0 || n2 >= bloblen || n2 < n1) {
+    if (!quiet) {
+      semsg(_(e_blobidx), n2);
+    }
+    return FAIL;
+  }
+  return OK;
+}
+
 /// Set bytes "n1" to "n2" (inclusive) in "dest" to the value of "src".
 /// Caller must make sure "src" is a blob.
 /// Returns FAIL if the number of bytes does not match.

src/nvim/testdir/test_blob.vim

@@ -76,16 +76,47 @@ func Test_blob_assign()
   END
   call CheckLegacyAndVim9Success(lines)
 
-  " TODO: move to above once it works
+  let lines =<< trim END
-  let b = 0zDEADBEEF
+      VAR b = 0zDEADBEEF
-  call assert_fails('let b[2 : 3] = 0z112233', 'E972:')
+      LET b[2 : 3] = 0z112233
-  call assert_fails('let b[2 : 3] = 0z11', 'E972:')
+  END
-  call assert_fails('let b[3 : 2] = 0z', 'E979:')
+  call CheckLegacyAndVim9Failure(lines, 'E972:')
 
-  call assert_fails('let b ..= 0z33', 'E734:')
+  let lines =<< trim END
-  call assert_fails('let b ..= "xx"', 'E734:')
+      VAR b = 0zDEADBEEF
-  call assert_fails('let b += "xx"', 'E734:')
+      LET b[2 : 3] = 0z11
-  call assert_fails('let b[1 : 1] ..= 0z55', 'E734:')
+  END
+  call CheckLegacyAndVim9Failure(lines, 'E972:')
+
+  let lines =<< trim END
+      VAR b = 0zDEADBEEF
+      LET b[3 : 2] = 0z
+  END
+  call CheckLegacyAndVim9Failure(lines, 'E979:')
+
+  let lines =<< trim END
+      VAR b = 0zDEADBEEF
+      LET b ..= 0z33
+  END
+  call CheckLegacyAndVim9Failure(lines, ['E734:', 'E1019:', 'E734:'])
+
+  let lines =<< trim END
+      VAR b = 0zDEADBEEF
+      LET b ..= "xx"
+  END
+  call CheckLegacyAndVim9Failure(lines, ['E734:', 'E1019:', 'E734:'])
+
+  let lines =<< trim END
+      VAR b = 0zDEADBEEF
+      LET b += "xx"
+  END
+  call CheckLegacyAndVim9Failure(lines, ['E734:', 'E1012:', 'E734:'])
+
+  let lines =<< trim END
+      VAR b = 0zDEADBEEF
+      LET b[1 : 1] ..= 0z55
+  END
+  call CheckLegacyAndVim9Failure(lines, ['E734:', 'E1183:', 'E734:'])
 endfunc
 
 func Test_blob_get_range()

src/nvim/testdir/vim9.vim

@@ -98,9 +98,9 @@ endfunc
 " Use ' #"' for a comment
 func CheckLegacyAndVim9Failure(lines, error)
   if type(a:error) == type('string')
-    let legacyError = error
+    let legacyError = a:error
   else
-    let legacyError = error[0]
+    let legacyError = a:error[0]
   endif
 
   let legacylines = a:lines->deepcopy()->map({_, v ->