Fix bug in dlerror second consecutive call

According to the specs, a second consecutive call
to dlerror should always return NULL .
This was the case in dlfcn-win32 before
https://github.com/dlfcn-win32/dlfcn-win32/pull/20
introduce a regression that caused dlerror to crash
on the second consecutive call.

In this commit the issue is fixed as suggested in
https://github.com/dlfcn-win32/dlfcn-win32/issues/34
and a regression test has been added.

1 files changed, 6 insertions, 0 deletions

diff --git a/dlfcn.c b/dlfcn.c
index 4367bd7..a91e963 100644
--- a/dlfcn.c
+++ b/dlfcn.c
@@ -431,6 +431,12 @@ end:
 char *dlerror( void )

 {

     char *error_pointer = dlerror_buffer;

+    

+    /* If this is the second consecutive call to dlerror, return NULL */

+    if (current_error == NULL)

+    {

+        return NULL;

+    }

 

 #ifdef UNICODE

     errno_t err = 0;