FIX: lexer corrupting memory or crashing on LOAD event after failing …

…to validate a token.
red · Jun 8, 2020 · 0525eb1 · 0525eb1
1 parent 3d23acd
commit 0525eb1
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Showing 2 changed files with 11 additions and 1 deletion.
diff --git a/runtime/lexer.reds b/runtime/lexer.reds
@@ -2124,7 +2124,8 @@ lexer: context [
 					do-load: as loader! loaders/index
 					if :do-load <> null [
 						catch LEX_ERR [do-load lex s p flags yes]
-						if events? [
+						if all [events? system/thrown <> LEX_ERR][
+							assert all [lex/tail > lex/head lex/tail > lex/buffer]
 							slot: lex/tail - 1
 							unless fire-event lex EVT_LOAD TYPE_OF(slot) slot s lex/in-pos [lex/tail: slot]
 						]

diff --git a/tests/source/units/lexer-test.red b/tests/source/units/lexer-test.red
@@ -1155,6 +1155,15 @@ Red [
 		    load integer! datatype! 1 3
 		]
 
+	--test-- "tt-17"
+		clear logs
+		--assert [] = transcode/trace {#"^^(00) a"} :lex-logger
+		--assert logs = [
+		    prescan char! datatype! 1 1x10 
+		    error error! datatype! 1 8x10 
+		    scan char! datatype! 1 1x11 
+		    error error! datatype! 1 8x10
+		]
 
 ===end-group===