Fix for Mantis bug 1930

inform7/Tests/Test Problems/PM_TableCorrFruitless2

@@ -0,0 +1,14 @@
+Lab is a room.
+
+Fooing is an action applying to one topic.
+Understand "foo [text]" as fooing.  
+
+Check fooing:
+	if there is a token of the topic understood in the Table of Foo:
+		say "There is."
+
+Table of Foo
+token (text)
+"blah"
+
+Test me with "foo blah".

inform7/Tests/Test Problems/_Results_Ideal/PM_TableCorrFruitless2.txt

@@ -0,0 +1,20 @@
+Inform 7 v10.1.0 has started.
+I've now read your source text, which is 47 words long.
+I've also read Basic Inform by Graham Nelson, which is 7691 words long.
+I've also read English Language by Graham Nelson, which is 2328 words long.
+I've also read Standard Rules by Graham Nelson, which is 32092 words long.
+Problem__ PM_TableCorrFruitless2
+  >--> In the sentence 'if there is a token of the topic understood in the
+    Table of Foo' (source text, line 7), you seem to be looking up a
+    corresponding entry in a table: but you're looking up a snippet of a
+    command (a snippet) in a column of text. Although those look the same, they
+    really aren't, and no match can be made. (You might be able to fix matters
+    by converting the snippet to text, say writing '"[the topic understood]"'
+    in place of 'the topic understood'.)
+    I was trying to match this phrase:
+      there is (a token of the topic understood in the table of foo - a table
+    entry) 
+    I recognised:
+    a token of the topic understood in the table of foo = a table entry, holding
+    a text
+Inform 7 has finished.

inform7/values-module/Chapter 5/Dash.w

@@ -1997,6 +1997,24 @@ a property when recovering from other problems.
 				"since the entry is taken from something which isn't a table.");
 			return NEVER_MATCH;
 		}
+		if ((K_snippet) &&
+			(Kinds::eq(key_kind, K_snippet)) && (Kinds::eq(col_contents_kind, K_text))) {
+			THIS_IS_A_GROSSER_THAN_GROSS_PROBLEM;
+			Problems::quote_source(1, current_sentence);
+			Problems::quote_kind(2, col_contents_kind);
+			Problems::quote_kind(3, key_kind);
+			Problems::quote_wording(4, Node::get_text(p->down->next->next));
+			StandardProblems::handmade_problem(Task::syntax_tree(), _p_(PM_TableCorrFruitless2));
+			Problems::issue_problem_segment(
+				"In the sentence %1, you seem to be looking up a corresponding "
+				"entry in a table: but you're looking up a snippet of a command "
+				"(%3) in a column of text. Although those look the same, they "
+				"really aren't, and no match can be made. (You might be able to "
+				"fix matters by converting the snippet to text, say writing '\"[%4]\"' "
+				"in place of '%4'.)");
+			Problems::issue_problem_end();
+			return NEVER_MATCH;
+		}
 		if (Kinds::compatible(key_kind, col_contents_kind) == NEVER_MATCH) {
 			THIS_IS_A_GROSSER_THAN_GROSS_PROBLEM;
 			Problems::quote_source(1, current_sentence);