dwarflint: Fix iteration over low-level attributes

- this to allow (certainly bogus, but anyway) attribute name == 0
- test case that triggers this

3 files changed, 7 insertions, 3 deletions

diff --git a/dwarflint/check_debug_info.cc b/dwarflint/check_debug_info.cc
index 6672c8c8..348dad0d 100644
--- a/dwarflint/check_debug_info.cc
+++ b/dwarflint/check_debug_info.cc
@@ -642,7 +642,7 @@ namespace
 
 	/* Attribute values.  */
 	for (struct abbrev_attrib *it = abbrev->attribs;
-	     it->name != 0; ++it)
+	     it->name != 0 || it->form != 0; ++it)
 	  {
 	    where.ref = &it->where;
 
@@ -1097,7 +1097,7 @@ check_debug_info::check_debug_info (checkstack &stack, dwarflint &lint)
 	    if (!it->second.abbr[i].used)
 	      wr_message (it->second.abbr[i].where,
 			  cat (mc_impact_3, mc_acc_bloat, mc_abbrevs))
-		<< ": abbreviation is never used." << std::endl;
+		<< "abbreviation is never used." << std::endl;
     }
 
   // re-link CUs so that they form a chain again.  This is to
diff --git a/dwarflint/tests/garbage-3.bz2 b/dwarflint/tests/garbage-3.bz2
new file mode 100644
index 00000000..ad66a414
--- /dev/null
+++ b/dwarflint/tests/garbage-3.bz2
diff --git a/dwarflint/tests/run-bad.sh b/dwarflint/tests/run-bad.sh
index 871fe551..38b9be1a 100755
--- a/dwarflint/tests/run-bad.sh
+++ b/dwarflint/tests/run-bad.sh
@@ -27,7 +27,7 @@
 
 srcdir=$srcdir/tests
 
-testfiles hello.bad-1 hello.bad-3 garbage-1 garbage-2
+testfiles hello.bad-1 hello.bad-3 garbage-1 garbage-2 garbage-3
 
 testrun_compare ./dwarflint hello.bad-1 <<EOF
 error: .debug_info: DIE 0x83: abbrev section at 0x0 doesn't contain code 83.
@@ -50,3 +50,7 @@ EOF
 testrun_compare ./dwarflint garbage-2 <<EOF
 error: .debug_info: CU 0: toplevel DIE must be either compile_unit or partial_unit.
 EOF
+
+testrun_compare ./dwarflint --check=@low garbage-3 <<EOF
+error: .debug_abbrev: abbr. attribute 0xc: invalid or unknown name 0x0.
+EOF