be a bit more descriptive about what triggered the error

Author: alandekok

src/lib/server/tmpl_tokenize.c

@@ -1565,7 +1565,7 @@ static fr_slen_t tmpl_attr_parse_filter(tmpl_attr_error_t *err, tmpl_attr_t *ar,
 		if (slen <= 0) goto error;
 
 		if (!tmpl_is_attr(ar->ar_tmpl)) {
-			fr_strerror_const("Invalid array index");
+			fr_strerror_printf("Invalid array index '%s'", ar->ar_tmpl->name);
 			goto error;
 		}
 

src/tests/unit/condition/base.txt

@@ -526,10 +526,10 @@ match (&26.24757.84.9.5.15 == 0x1a99)
 #  Invalid array references.
 #
 condition &User-Name[a] == 'bob'
-match ERROR offset 12: Invalid array index
+match ERROR offset 12: Invalid array index 'a'
 
 condition &User-Name == &Filter-Id[a]
-match ERROR offset 26: Invalid array index
+match ERROR offset 26: Invalid array index 'a'
 
 #
 #  Bounds checks...
@@ -538,7 +538,7 @@ condition &User-Name[1001] == 'bob'
 match ERROR offset 12: Invalid array index '1001' (should be between 0-1000)
 
 condition &User-Name[-1] == 'bob'
-match ERROR offset 12: Invalid array index
+match ERROR offset 12: Invalid array index '-1'
 
 #
 #  Sometimes the attribute/condition parser needs to fallback to bare words

src/tests/unit/condition/filter.txt

@@ -25,7 +25,7 @@ condition &User-Name[n] == "foo"
 match (&User-Name[n] == "foo")
 
 condition &User-Name[-1] == "foo"
-match ERROR offset 12: Invalid array index
+match ERROR offset 12: Invalid array index '-1'
 
 #
 #  tmpl_dcursor.c has an assert which fails if you try to use

src/tests/unit/xlat/cond_base.txt

@@ -527,10 +527,10 @@ match ERROR offset 18: Unknown attributes not allowed here
 #  Invalid array references.
 #
 xlat_purify &User-Name[a] == 'bob'
-match ERROR offset 12: Invalid array index
+match ERROR offset 12: Invalid array index 'a'
 
 xlat_purify &User-Name == &Filter-Id[a]
-match ERROR offset 26: Invalid array index
+match ERROR offset 26: Invalid array index 'a'
 
 #
 #  Bounds checks...
@@ -539,7 +539,7 @@ xlat_purify &User-Name[1001] == 'bob'
 match ERROR offset 12: Invalid array index '1001' (should be between 0-1000)
 
 xlat_purify &User-Name[-1] == 'bob'
-match ERROR offset 12: Invalid array index
+match ERROR offset 12: Invalid array index '-1'
 
 #
 #  attributes MUST be prefixed with '&'.