[binutils-gdb] Fix build failure in symfile.c::unmap_overlay_command (GCC5 bug)

[Joel Brobecker <brobecke at sourceware dot org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=7a270e0c9ba0eb738a4c30258ab29c09963fcd4d

commit 7a270e0c9ba0eb738a4c30258ab29c09963fcd4d
Author: Alexander Klimov <alserkli@inbox.ru>
Date:   Tue Jan 27 19:56:45 2015 +0200

    Fix build failure in symfile.c::unmap_overlay_command (GCC5 bug)
    
    Compilation of (GDB) 7.9.50.20150127-cvs with (GCC) 5.0.0 20150127
    fails with
    
    In file included from symfile.c:32:0:
    symfile.c: In function 'unmap_overlay_command':
    objfiles.h:628:3: error: 'sec' may be used uninitialized in this
    function [-Werror=maybe-uninitialized]
       for (osect = objfile->sections; osect < objfile->sections_end; osect++) \
       ^
    symfile.c:3442:23: note: 'sec' was declared here
       struct obj_section *sec;
                           ^
    cc1: all warnings being treated as errors
    make[2]: *** [symfile.o] Error 1
    make[2]: Leaving directory `gdb/gdb'
    
    While the bug was reported to GCC as
    <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64823>,
    the attached patch simply initializes sec with NULL.
    
    gdb/ChangeLog:
    
            * symfile.c (unmap_overlay_command): Initialize sec to NULL.
    
    Tested on x86_64-linux.

Diff:
---
 gdb/ChangeLog | 4 ++++
 gdb/symfile.c | 2 +-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 03b8712..db4e0b1 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,7 @@
+2015-01-29  Joel Brobecker  <brobecker@adacore.com>  (tiny patch)
+
+	* symfile.c (unmap_overlay_command): Initialize sec to NULL.
+
 2015-01-27  Doug Evans  <dje@google.com>
 
 	* NEWS: Mention gdb.Objfile.username.
diff --git a/gdb/symfile.c b/gdb/symfile.c
index d55e361..86a758a 100644
--- a/gdb/symfile.c
+++ b/gdb/symfile.c
@@ -3439,7 +3439,7 @@ static void
 unmap_overlay_command (char *args, int from_tty)
 {
   struct objfile *objfile;
-  struct obj_section *sec;
+  struct obj_section *sec = NULL;
 
   if (!overlay_debugging)
     error (_("Overlay debugging not enabled.  "