Fix warning: Invalid entry in .debug_gdb_scripts section

$ gdb rustc
Reading symbols from rustc...Reading symbols from /usr/lib/debug/usr/bin/rustc.debug...done.
done.
warning: Invalid entry in .debug_gdb_scripts section

/usr/bin/rustc
Section Headers:
  [Nr] Name              Type            Address          Off    Size   ES Flg Lk Inf Al
  [15] .debug_gdb_scripts PROGBITS        00000000000008ed 0008ed 000022 00 AMS  0   0  1

/usr/lib/debug/usr/bin/rustc.debug
Section Headers:
  [Nr] Name              Type            Address          Off    Size   ES Flg Lk Inf Al
  [15] .debug_gdb_scripts NOBITS          00000000000008ed 000280 000022 00 AMS  0   0  1

There remains questionable whether bfd_get_section_by_name() should not return
an error for !SEC_LOAD but I haven't investigated that.

gdb/ChangeLog
2017-03-29  Jan Kratochvil  <jan.kratochvil@redhat.com>

	* auto-load.c (auto_load_section_scripts): Check SEC_HAS_CONTENTS.

gdb/testsuite/ChangeLog
2017-03-29  Jan Kratochvil  <jan.kratochvil@redhat.com>

	* gdb.python/py-section-script.exp (sepdebug): New testcases.

4 files changed, 48 insertions, 1 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 23df636..bfa5358 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,7 @@
+2017-03-29  Jan Kratochvil  <jan.kratochvil@redhat.com>
+
+	* auto-load.c (auto_load_section_scripts): Check SEC_HAS_CONTENTS.
+
 2017-03-29  Yao Qi  <yao.qi@linaro.org>
 
 	* gdbthread.h (struct thread_info): Declare constructor and
diff --git a/gdb/auto-load.c b/gdb/auto-load.c
index 56914c8..edaf264 100644
--- a/gdb/auto-load.c
+++ b/gdb/auto-load.c
@@ -1174,7 +1174,8 @@ auto_load_section_scripts (struct objfile *objfile, const char *section_name)
   bfd_byte *data = NULL;
 
   scripts_sect = bfd_get_section_by_name (abfd, section_name);
-  if (scripts_sect == NULL)
+  if (scripts_sect == NULL
+      || (bfd_get_section_flags (abfd, scripts_sect) & SEC_HAS_CONTENTS) == 0)
     return;
 
   if (!bfd_get_full_section_contents (abfd, scripts_sect, &data))
diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index 5241a27..eb543eb 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2017-03-29  Jan Kratochvil  <jan.kratochvil@redhat.com>
+
+	* gdb.python/py-section-script.exp (sepdebug): New testcases.
+
 2017-03-28  Anton Kolesov  <anton.kolesov@synopsys.com>
 
 	* gdb.arch/arc-analyze-prologue.S: New file.
diff --git a/gdb/testsuite/gdb.python/py-section-script.exp b/gdb/testsuite/gdb.python/py-section-script.exp
index 52e1e3e..6707156 100644
--- a/gdb/testsuite/gdb.python/py-section-script.exp
+++ b/gdb/testsuite/gdb.python/py-section-script.exp
@@ -114,3 +114,41 @@ gdb_test "continue" ".*Breakpoint.*"
 gdb_test "print ss" " = a=<1> b=<2>"
 
 gdb_test "test-cmd 1 2 3" "test-cmd output, arg = 1 2 3"
+
+
+# eu-strip creates NOBITS .debug_gdb_scripts sections in the debug files.
+# Make sure those are ignored silently.
+
+with_test_prefix "sepdebug" {
+    gdb_exit
+
+    set result [catch "exec eu-strip -g -f ${binfile}.debug ${binfile}" output]
+    verbose "result is $result"
+    verbose "output is $output"
+    if {$result != 0 || $output != ""} {
+	unsupported "cannot produce separate debug info files"
+	return
+    }
+
+    gdb_start
+    gdb_reinitialize_dir $srcdir/$subdir
+
+    gdb_test_no_output "set auto-load safe-path ${remote_python_file}:${binfile}" \
+	"set auto-load safe-path"
+    set test "load sepdebug"
+    gdb_test_multiple "file $binfile" $test {
+	-re "\r\nwarning: Invalid entry in \\.debug_gdb_scripts section.*\r\n$gdb_prompt $" {
+	    fail $test
+	}
+	-re "done\\.\r\n$gdb_prompt $" {
+	    pass $test
+	}
+    }
+
+    # Again, with a regexp this time.
+    gdb_test "info auto-load python-scripts ${testfile}" "Yes.*${testfile}.py.*"
+
+    # Again, with a regexp that matches no scripts.
+    gdb_test "info auto-load python-scripts no-script-matches-this" \
+      "No auto-load scripts matching no-script-matches-this."
+}