Merge pull request #19969 from thofma/th/19963

Fix jl_free(NULL)

Author: JeffBezanson

src/gc.c

@@ -2088,9 +2088,11 @@ JL_DLLEXPORT void *jl_calloc(size_t nm, size_t sz)
 
 JL_DLLEXPORT void jl_free(void *p)
 {
-    int64_t *pp = (int64_t *)p - 2;
-    size_t sz = pp[0];
-    jl_gc_counted_free(pp, sz);
+    if (p != NULL) {
+        int64_t *pp = (int64_t *)p - 2;
+        size_t sz = pp[0];
+        jl_gc_counted_free(pp, sz);
+    }
 }
 
 JL_DLLEXPORT void *jl_realloc(void *p, size_t sz)

test/core.jl

@@ -4862,3 +4862,12 @@ end
 @test_throws ErrorException isless(MyTime(1), now())
 
 end
+
+# issue #15240
+
+p15240 = ccall(:jl_realloc, Ptr{Void}, (Ptr{Void}, Csize_t), C_NULL, 10)
+ccall(:jl_free, Void, (Ptr{Void}, ), p15240)
+
+# issue #19963
+
+ccall(:jl_free, Void, (Ptr{Void}, ), C_NULL)