From e909fb2179724b5619213520ca46cc31b4e6713b Mon Sep 17 00:00:00 2001
From: Robin Haberkorn <robin.haberkorn@googlemail.com>
Date: Thu, 20 Nov 2014 05:08:19 +0100
Subject: Throw error when a macro terminates while a local q-reg is edited.

This is only a problem if the macro created the local Q-Register table
(i.e. not when called with ":M") but resulted in segfaults.
Since we do not want to save in a Q-Reg whether it is local
(and that wouldn't suffice anyway), we do it in the Q-Register table
cleanup. The corresponding QRegisterTable::clear() must be called
explicitly, since the RBTree::clear() called on destruction does not
and cannot throw errors.
If QRegisterTable::clear() has been called successfully, the default object
destructor will not do much. If it has thrown an error, the destructor
will clean up the remaining Q-Registers.
---
 src/parser.cpp | 40 ++++++++++++++++++++++++++--------------
 1 file changed, 26 insertions(+), 14 deletions(-)

(limited to 'src/parser.cpp')

diff --git a/src/parser.cpp b/src/parser.cpp
index 0b11721..35b6add 100644
--- a/src/parser.cpp
+++ b/src/parser.cpp
@@ -146,25 +146,37 @@ Execute::macro(const gchar *macro, bool locals)
 	try {
 		step(macro, strlen(macro));
 
-		if (Goto::skip_label) {
-			Error error("Label \"%s\" not found",
-			            Goto::skip_label);
-			error.pos = strlen(macro);
-			String::get_coord(macro, error.pos,
-					  error.line, error.column);
-			throw error;
-		}
+		/*
+		 * Subsequent errors must still be
+		 * attached to this macro invocation.
+		 */
+		try {
+			if (Goto::skip_label)
+				throw Error("Label \"%s\" not found",
+				            Goto::skip_label);
+
+			if (States::current != &States::start)
+				/*
+				 * can only happen if we returned because
+				 * of macro end
+				 */
+				throw Error("Unterminated command");
 
-		if (States::current != &States::start) {
-			Error error("Unterminated command");
 			/*
-			 * can only happen if we returned because
-			 * of macro end
+			 * This handles the problem of Q-Registers
+			 * local to the macro invocation being edited
+			 * when the macro terminates.
+			 * QRegisterTable::clear() throws an error
+			 * if this happens and the Q-Reg editing
+			 * is undone.
 			 */
+			if (locals)
+				QRegisters::locals->clear();
+		} catch (Error &error) {
 			error.pos = strlen(macro);
 			String::get_coord(macro, error.pos,
-			                  error.line, error.column);
-			throw error;
+					  error.line, error.column);
+			throw; /* forward */
 		}
 	} catch (...) {
 		g_free(Goto::skip_label);
-- 
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