[[ Bug 20488 ]] Ensure put throws when expecting preposition

montegoulding · montegoulding · commit ec1cd74eb830 · 2018-03-23T13:33:42.000+11:00
This patch ensures that the put command throws an error if it parses
a token when expecting a preposition and it isn't one. Previously
the command backed up and returned normal resulting in the anomaly that
anything after `put &lt;expression&gt;` could be treated as a second statement
without a newline or `;` present.
diff --git a/docs/notes/bugfix-20488.md b/docs/notes/bugfix-20488.md
@@ -0,0 +1 @@
+# Ensure the put command throws an error when a preposition is expected and not found
diff --git a/engine/src/cmds.cpp b/engine/src/cmds.cpp
@@ -844,8 +844,8 @@ Parse_stat MCPut::parse(MCScriptPoint &sp)
 		
 	if (sp.lookup(SP_FACTOR, te) != PS_NORMAL || te->type != TT_PREP)
 	{
-		sp.backup();
-		return PS_NORMAL;
+        MCperror->add(PE_PUT_BADPREP, sp);
+        return PS_ERROR;
 	}
 	prep = (Preposition_type)te->which;
 	if (prep != PT_BEFORE && prep != PT_INTO && prep != PT_AFTER)
diff --git a/tests/lcs/parser/put.parsertest b/tests/lcs/parser/put.parsertest
@@ -0,0 +1,24 @@
+%% Copyright (C) 2018 LiveCode Ltd.
+%%
+%% This file is part of LiveCode.
+%%
+%% LiveCode is free software; you can redistribute it and/or modify it under
+%% the terms of the GNU General Public License v3 as published by the Free
+%% Software Foundation.
+%%
+%% LiveCode is distributed in the hope that it will be useful, but WITHOUT ANY
+%% WARRANTY; without even the implied warranty of MERCHANTABILITY or
+%% FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+%% for more details.
+%%
+%% You should have received a copy of the GNU General Public License
+%% along with LiveCode.  If not see <http://www.gnu.org/licenses/>.
+
+%TEST PutPreposition
+on parse_test
+   local tFoo, tBar
+   put tFoo tBar %{AFTER_BADPREP}
+end parse_test
+%EXPECT PASS
+%ERROR PE_PUT_BADPREP AT AFTER_BADPREP
+%ENDTEST

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1 @@`
	`1`	`+# Ensure the put command throws an error when a preposition is expected and not found`
Original file line number	Diff line number	Diff line change
`@@ -844,8 +844,8 @@ Parse_stat MCPut::parse(MCScriptPoint &sp)`
`844`	`844`
`845`	`845`	`if (sp.lookup(SP_FACTOR, te) != PS_NORMAL \|\| te->type != TT_PREP)`
`846`	`846`	`{`
`847`		`- sp.backup();`
`848`		`- return PS_NORMAL;`
	`847`	`+ MCperror->add(PE_PUT_BADPREP, sp);`
	`848`	`+ return PS_ERROR;`
`849`	`849`	`}`
`850`	`850`	`prep = (Preposition_type)te->which;`
`851`	`851`	`if (prep != PT_BEFORE && prep != PT_INTO && prep != PT_AFTER)`