[binutils-gdb] Check for null result from gdb_demangle

[gdb-buildbot@sergiodj.net]

*** TEST RESULTS FOR COMMIT 4f180d5396741eb65badba70cf5077b7d48f8641 ***

commit 4f180d5396741eb65badba70cf5077b7d48f8641
Author:     Ali Tamur via gdb-patches <gdb-patches@sourceware.org>
AuthorDate: Fri Feb 21 08:19:21 2020 -0700
Commit:     Tom Tromey <tromey@adacore.com>
CommitDate: Fri Feb 21 08:19:21 2020 -0700

    Check for null result from gdb_demangle
    
    I am sending this patch on behalf of kmoy@google.com, who discovered the bug
    and wrote the fix.
    
    gdb_demangle can return null for strings that don't properly demangle. The null
    check was mistakenly removed in commit 43816ebc335. Without this check, GDB
    aborts when loading symbols from some binaries.
    
    gdb/ChangeLog
    2020-02-21  Ali Tamur  <tamur@google.com>
    
            * dwarf2/read.c (dwarf2_name): Add null check.

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 748788acac..d480ff4e15 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,7 @@
+2020-02-21  Ali Tamur  <tamur@google.com>
+
+	* dwarf2/read.c (dwarf2_name): Add null check.
+
 2020-02-20  Tom Tromey  <tom@tromey.com>
 
 	* dwarf2/read.c (dwarf2_find_containing_comp_unit): Use ">", not
diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c
index f998fe6b8d..46d510eb27 100644
--- a/gdb/dwarf2/read.c
+++ b/gdb/dwarf2/read.c
@@ -21756,6 +21756,8 @@ dwarf2_name (struct die_info *die, struct dwarf2_cu *cu)
 	    {
 	      gdb::unique_xmalloc_ptr<char> demangled
 		(gdb_demangle (DW_STRING (attr), DMGL_TYPES));
+	      if (demangled == nullptr)
+		return nullptr;
 
 	      const char *base;