prefer "allowed" to "terminals"

If we want to parse

	&Service-Type = Framed-User

then we don't want to parse it as

	(&Service - Type) = (Framed - User)

or

	(&Service-Type = Framed) - User

etc.

The tmpl_afrom_attr_substr() calls fr_dict_attr_by_name_substr()
which calls fr_dict_attr_by_name_substr(), which then ignores
terminals.  So this change makes parsing the RHS enum name behave
the same as parsing the LHS attribute name.

diff --git a/src/lib/util/sbuff.c b/src/lib/util/sbuff.c
index b6586bf98b258ff1fb1f22e836495fed987e5021..22bb7cca77d2fb02fdd9bfa4ae06012269bd14e9 100644 (file)
--- a/src/lib/util/sbuff.c
+++ b/src/lib/util/sbuff.c
@@ -1691,8 +1691,45 @@ size_t fr_sbuff_adv_past_allowed(fr_sbuff_t *sbuff, size_t len, bool
 
                end = CONSTRAINED_END(sbuff, len, total);
                p = sbuff->p;
-               while ((p < end) && allowed[(uint8_t)*p] &&
-                      ((needle_len == 0) || !fr_sbuff_terminal_search(sbuff, p, idx, tt, needle_len))) p++;
+               while ((p < end) && allowed[(uint8_t)*p]) {
+                       if (needle_len == 0) {
+                               p++;
+                               continue;
+                       }
+
+                      /*
+                       *       If this character is allowed, BUT is also listed as a one-character terminal,
+                       *       then we still allow it.  This decision implements "greedy" parsing.
+                       */
+                      if (fr_sbuff_terminal_search(sbuff, p, idx, tt, 1)) {
+                              p++;
+                              continue;
+                      }
+
+                      /*
+                       *       Otherwise if the next *set* of characters) is not in the terminals, then
+                       *       allow the current character.
+                       */
+                      if (!fr_sbuff_terminal_search(sbuff, p, idx, tt, needle_len)) {
+                              p++;
+                              continue;
+                      }
+
+                      /*
+                       *       The character is allowed, and is NOT listed as a terminal character by itself.
+                       *       However, it is part of a multi-character terminal sequence.  We therefore
+                       *       stop.
+                       *
+                       *       This decision allows us to parse things like "Framed-User", where we might
+                       *       normally stop at the "-".  However, we will still stop at "Framed-=User", as
+                       *       "-=" may be a terminal sequence.
+                       *
+                       *       There is no perfect solution here, other than to fix the input grammer so that
+                       *       it has no ambiguity.  Since we can't do that, we choose to err on the side of
+                       *       allowing the existing grammar, where it makes sense
+                       */
+                      break;
+               }
 
                total += fr_sbuff_set(sbuff, p);
                if (p != end) break;            /* stopped early, break */