[./src/input.cc:1268]: (error) Dangerous iterator usage.

[John W. Eaton]

On 27-Jan-2011, CdeMills wrote:

| 
| Consider the enclosed program. It reads data from a map and increase the
| iterator by one position. If the data just read is just before the last, the
| last is destroyed. Yet upon next read, the data returned is the one just
| destroyed!
| 
| It seems that mixing map.erase() and iterators is unsafe. OTOH, I don't
| understand the logic around line 1268: 
|  if (is_valid_function (hook_fcn)) result is false, then we erase the next
| element ???

Right, I don't think the intent was to remove the next element.  It
looks like a bug to me.

How about the following change?

jwe

# HG changeset patch
# User John W. Eaton <address@hidden>
# Date 1296118693 18000
# Node ID f747f66bda2f7dbb30dc41270cc5dc9d639b2381
# Parent  3592c57fa6a85a09adb16b6b14e341b908c2ab91
input.cc (input_event_hook): fix incorrect use of iterator

diff --git a/src/ChangeLog b/src/ChangeLog
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,8 @@
+2011-01-27  John W. Eaton  <address@hidden>
+
+       * input.cc (input_event_hook): Fix incorrect use of iterator.
+       Reported by Pascal Dupuis <address@hidden>.
+
 2011-01-26  John W. Eaton  <address@hidden>
 
        * lex.ll, graphics.cc, gl-render.cc, ov-mex-fcn.h, graphics.h.in:
diff --git a/src/input.cc b/src/input.cc
--- a/src/input.cc
+++ b/src/input.cc
@@ -1255,7 +1255,7 @@
           std::string hook_fcn = p->first;
           octave_value user_data = p->second;
 
-          p++;
+          hook_fcn_map_type::iterator q = p++;
 
           if (is_valid_function (hook_fcn))
             {
@@ -1265,7 +1265,7 @@
                 feval (hook_fcn, octave_value_list (), 0);
             }
           else
-            hook_fcn_map.erase (p);
+            hook_fcn_map.erase (q);
         }
 
       if (hook_fcn_map.empty ())