Fix bug reported by Dan DuVarney, based on a patch by himself.

POSIX says:
If no dynamic linking errors have occurred since the last invocation of
dlerror(), dlerror() shall return NULL.

The code was returning an empty string. The way dlerror( ) returns
the error string has been changed.

1 files changed, 10 insertions, 9 deletions

diff --git a/dlfcn.c b/dlfcn.c
index f0efc22..14eecef 100644
--- a/dlfcn.c
+++ b/dlfcn.c
@@ -105,7 +105,7 @@ static void global_rem( HMODULE hModule )
  * the limit.

  */

 static char error_buffer[65535];

-static int dlerror_was_last_call;

+static char *current_error;

 

 static int copy_string( char *dest, int dest_size, const char *src )

 {

@@ -153,6 +153,8 @@ static void save_err_str( const char *str )
         if( error_buffer[pos-2] == '\r' && error_buffer[pos-1] == '\n' )

             error_buffer[pos-2] = '\0';

     }

+

+    current_error = error_buffer;

 }

 

 static void save_err_ptr( const void *ptr )

@@ -169,7 +171,7 @@ void *dlopen( const char *file, int mode )
     HMODULE hModule;

     UINT uMode;

 

-    dlerror_was_last_call = 0;

+    current_error = NULL;

 

     /* Do not let Windows display the critical-error-handler message box */

     uMode = SetErrorMode( SEM_FAILCRITICALERRORS );

@@ -238,7 +240,7 @@ int dlclose( void *handle )
     HMODULE hModule = (HMODULE) handle;

     BOOL ret;

 

-    dlerror_was_last_call = 0;

+    current_error = NULL;

 

     ret = FreeLibrary( hModule );

 

@@ -260,7 +262,7 @@ void *dlsym( void *handle, const char *name )
 {

     FARPROC symbol;

 

-    dlerror_was_last_call = 0;

+    current_error = NULL;

 

     symbol = GetProcAddress( handle, name );

 

@@ -300,13 +302,12 @@ void *dlsym( void *handle, const char *name )
 

 char *dlerror( void )

 {

+    char *error_pointer = current_error;

+

     /* POSIX says that invoking dlerror( ) a second time, immediately following

      * a prior invocation, shall result in NULL being returned.

      */

-    if( dlerror_was_last_call )

-        return NULL;

-

-    dlerror_was_last_call = 1;

+    current_error = NULL;

 

-    return error_buffer;

+    return error_pointer;

 }