precompile: avoid a potential crash when adding methods (JuliaLang#35378)

vtjnash · web-flow · commit 8a55a27ea7f9 · 2020-04-09T21:36:28.000-04:00
fixes JuliaLang#29859
diff --git a/src/gf.c b/src/gf.c
@@ -1356,7 +1356,8 @@ static int check_ambiguous_visitor(jl_typemap_entry_t *oldentry, struct typemap_
 
     // ok: record that this method definition is being partially replaced
     // (either with a real definition, or an ambiguity error)
-    if (shadowed) {
+    // be careful not to try to scan something from the current dump-reload though
+    if (shadowed && oldentry->min_world != closure->newentry->min_world) {
         if (closure->shadowed == NULL) {
             closure->shadowed = (jl_value_t*)oldentry;
         }

Original file line number	Diff line number	Diff line change
`@@ -1356,7 +1356,8 @@ static int check_ambiguous_visitor(jl_typemap_entry_t *oldentry, struct typemap_`
`1356`	`1356`
`1357`	`1357`	`// ok: record that this method definition is being partially replaced`
`1358`	`1358`	`// (either with a real definition, or an ambiguity error)`
`1359`		`- if (shadowed) {`
	`1359`	`+ // be careful not to try to scan something from the current dump-reload though`
	`1360`	`+ if (shadowed && oldentry->min_world != closure->newentry->min_world) {`
`1360`	`1361`	`if (closure->shadowed == NULL) {`
`1361`	`1362`	`closure->shadowed = (jl_value_t*)oldentry;`
`1362`	`1363`	`}`