Index: compiler-rt/trunk/lib/asan/scripts/asan_symbolize.py
===================================================================
--- compiler-rt/trunk/lib/asan/scripts/asan_symbolize.py
+++ compiler-rt/trunk/lib/asan/scripts/asan_symbolize.py
@@ -431,10 +431,13 @@
     assert result
     return result
 
-  def get_symbolized_lines(self, symbolized_lines):
+  def get_symbolized_lines(self, symbolized_lines, inc_frame_counter=True):
     if not symbolized_lines:
+      if inc_frame_counter:
+        self.frame_no += 1
       return [self.current_line]
     else:
+      assert inc_frame_counter
       result = []
       for symbolized_frame in symbolized_lines:
         result.append('    #%s %s' % (str(self.frame_no), symbolized_frame.rstrip()))
@@ -464,15 +467,17 @@
     match = re.match(stack_trace_line_format, line)
     if not match:
       logging.debug('Line "{}" does not match regex'.format(line))
-      return [self.current_line]
+      # Not a frame line so don't increment the frame counter.
+      return self.get_symbolized_lines(None, inc_frame_counter=False)
     logging.debug(line)
     _, frameno_str, addr, binary, offset = match.groups()
+
     if not self.using_module_map and not os.path.isabs(binary):
       # Do not try to symbolicate if the binary is just the module file name
       # and a module map is unavailable.
       # FIXME(dliew): This is currently necessary for reports on Darwin that are
       # partially symbolicated by `atos`.
-      return [self.current_line]
+      return self.get_symbolized_lines(None)
     arch = ""
     # Arch can be embedded in the filename, e.g.: "libabc.dylib:x86_64h"
     colon_pos = binary.rfind(":")
@@ -491,7 +496,7 @@
     if binary is None:
       # The binary filter has told us this binary can't be symbolized.
       logging.debug('Skipping symbolication of binary "%s"', original_binary)
-      return [self.current_line]
+      return self.get_symbolized_lines(None)
     symbolized_line = self.symbolize_address(addr, binary, offset, arch)
     if not symbolized_line:
       if original_binary != binary:
Index: compiler-rt/trunk/test/asan/TestCases/Posix/asan_symbolize_script/plugin_wrong_frame_number_bug.cpp
===================================================================
--- compiler-rt/trunk/test/asan/TestCases/Posix/asan_symbolize_script/plugin_wrong_frame_number_bug.cpp
+++ compiler-rt/trunk/test/asan/TestCases/Posix/asan_symbolize_script/plugin_wrong_frame_number_bug.cpp
@@ -0,0 +1,48 @@
+// This test case checks for an old bug when using plug-ins that caused
+// the stack numbering to be incorrect.
+
+// RUN: %clangxx_asan -O0 -g %s -o %t
+// RUN: %env_asan_opts=symbolize=0 not %run %t DUMMY_ARG > %t.asan_report 2>&1
+// RUN: %asan_symbolize --log-level debug --log-dest %t_debug_log_output.txt -l %t.asan_report --plugins %S/plugin_wrong_frame_number_bug.py > %t.asan_report_sym
+// RUN: FileCheck --input-file=%t.asan_report_sym %s
+
+#include <stdlib.h>
+
+int* p;
+extern "C" {
+
+void bug() {
+  free(p);
+}
+
+void foo(bool call_bug) {
+  if (call_bug)
+    bug();
+}
+
+// This indirection exists so that the call stack
+// is reliably large enough.
+void do_access_impl() {
+  *p = 42;
+}
+
+void do_access() {
+  do_access_impl();
+}
+
+int main(int argc, char** argv) {
+  p = (int*) malloc(sizeof(p));
+  foo(argc > 1);
+  do_access();
+  free(p);
+  return 0;
+}
+}
+
+// Check that the numbering of the stackframes is correct.
+
+// CHECK: AddressSanitizer: heap-use-after-free
+// CHECK-NEXT: WRITE of size
+// CHECK-NEXT: #0 0x{{[0-9a-fA-F]+}}
+// CHECK-NEXT: #1 0x{{[0-9a-fA-F]+}} in do_access
+// CHECK-NEXT: #2 0x{{[0-9a-fA-F]+}} in main
Index: compiler-rt/trunk/test/asan/TestCases/Posix/asan_symbolize_script/plugin_wrong_frame_number_bug.py
===================================================================
--- compiler-rt/trunk/test/asan/TestCases/Posix/asan_symbolize_script/plugin_wrong_frame_number_bug.py
+++ compiler-rt/trunk/test/asan/TestCases/Posix/asan_symbolize_script/plugin_wrong_frame_number_bug.py
@@ -0,0 +1,31 @@
+import logging
+
+class FailOncePlugin(AsanSymbolizerPlugIn):
+  """
+    This is a simple plug-in that always claims
+    that a binary can't be symbolized on the first
+    call but succeeds for all subsequent calls.
+
+    This plug-in exists to reproduce an old bug
+    in the `asan_symbolize.py` script.
+
+    By failing the first symbolization request
+    we used to cause an early exit in `asan_symbolize.py`
+    that didn't increment the frame counter which
+    caused subsequent symbolization attempts to
+    print the wrong frame number.
+  """
+  def __init__(self):
+    self.should_fail = True
+    pass
+
+  def filter_binary_path(self, path):
+    logging.info('filter_binary_path called in NoOpPlugin')
+    if self.should_fail:
+      logging.info('Doing first fail')
+      self.should_fail = False
+      return None
+    logging.info('Doing succeed')
+    return path
+
+register_plugin(FailOncePlugin())