[PATCH] Fix memory leak in python.c:do_start_initialization

[Philipp Rudo <prudo@linux.vnet.ibm.com>]

When intializing Python the path to the python binary is build the
following way

progname = concat (ldirname (python_libdir), SLASH_STRING, "bin",
		   SLASH_STRING, "python", (char *) NULL);

This is problematic as both concat and ldirname allocate memory for the
string they return.  Thus the memory allocated by ldirname cannot be
accessed afterwards causing a memory leak.  Fix it by temporarily storing
libdir in a variable and xfree it after concat.

gdb/ChangeLog:
	python/python.c (do_start_initialization): Fix memory leak.
---
 gdb/python/python.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/gdb/python/python.c b/gdb/python/python.c
index 73fb3d0..6b16613 100644
--- a/gdb/python/python.c
+++ b/gdb/python/python.c
@@ -1535,7 +1535,7 @@ extern initialize_file_ftype _initialize_python;
 static bool
 do_start_initialization ()
 {
-  char *progname;
+  char *progname, *libdir;
 #ifdef IS_PY3K
   int i;
   size_t progsize, count;
@@ -1550,8 +1550,10 @@ do_start_initialization ()
      /foo/bin/python
      /foo/lib/pythonX.Y/...
      This must be done before calling Py_Initialize.  */
-  progname = concat (ldirname (python_libdir), SLASH_STRING, "bin",
+  libdir = ldirname (python_libdir);
+  progname = concat (libdir, SLASH_STRING, "bin",
 		     SLASH_STRING, "python", (char *) NULL);
+  xfree (libdir);
 #ifdef IS_PY3K
   oldloc = xstrdup (setlocale (LC_ALL, NULL));
   setlocale (LC_ALL, "");
-- 
2.8.4