diff --git a/changes/bug1345 b/changes/bug1345
new file mode 100644
index 0000000000..0c9375a35d
--- /dev/null
+++ b/changes/bug1345
@@ -0,0 +1,13 @@
+  o Minor bugfixes:
+    - On SIGHUP, do not clear out all TrackHostExits mappings, client DNS
+      cache entries, and virtual address mappings: that's what NEWNYM is
+      for.  Bugfix on Tor 0.1.0.1-rc; fixes bug 1345.
+    - When TrackHostExits is changed from a controller, remove any
+      mappings for hosts that should no longer have their exits tracked.
+      Bugfix on Tor 0.1.0.1-rc.
+    - When VirtualAddrNetwork option is changed from a controller,
+      remove any mappings for hosts that were automapped to
+      that network.  Bugfix on 0.1.1.19-rc.
+    - When one of the AutomapHosts* options is changed from a
+      controller, remove any mappings for hosts that should no longer be
+      automapped.  Bugfix on 0.2.0.1-alpha.
diff --git a/src/common/container.c b/src/common/container.c
index 09d4bb131f..ca49cbb170 100644
--- a/src/common/container.c
+++ b/src/common/container.c
@@ -215,6 +215,25 @@ smartlist_string_num_isin(const smartlist_t *sl, int num)
   return smartlist_string_isin(sl, buf);
 }
 
+/** Return true iff the two lists contain the same strings in the same
+ * order, or if they are both NULL. */
+int
+smartlist_strings_eq(const smartlist_t *sl1, const smartlist_t *sl2)
+{
+  if (sl1 == NULL)
+    return sl2 == NULL;
+  if (sl2 == NULL)
+    return 0;
+  if (smartlist_len(sl1) != smartlist_len(sl2))
+    return 0;
+  SMARTLIST_FOREACH(sl1, const char *, cp1, {
+      const char *cp2 = smartlist_get(sl2, cp1_sl_idx);
+      if (strcmp(cp1, cp2))
+        return 0;
+    });
+  return 1;
+}
+
 /** Return true iff <b>sl</b> has some element E such that
  * tor_memeq(E,<b>element</b>,DIGEST_LEN)
  */
diff --git a/src/common/container.h b/src/common/container.h
index b39d4ca07e..f5e42de764 100644
--- a/src/common/container.h
+++ b/src/common/container.h
@@ -42,6 +42,8 @@ int smartlist_string_pos(const smartlist_t *, const char *elt) ATTR_PURE;
 int smartlist_string_isin_case(const smartlist_t *sl, const char *element)
   ATTR_PURE;
 int smartlist_string_num_isin(const smartlist_t *sl, int num) ATTR_PURE;
+int smartlist_strings_eq(const smartlist_t *sl1, const smartlist_t *sl2)
+  ATTR_PURE;
 int smartlist_digest_isin(const smartlist_t *sl, const char *element)
   ATTR_PURE;
 int smartlist_overlap(const smartlist_t *sl1, const smartlist_t *sl2)
diff --git a/src/or/circuituse.c b/src/or/circuituse.c
index e68fb4fa82..86db7c3a02 100644
--- a/src/or/circuituse.c
+++ b/src/or/circuituse.c
@@ -1485,12 +1485,33 @@ link_apconn_to_circ(edge_connection_t *apconn, origin_circuit_t *circ,
   }
 }
 
-/** If an exit wasn't specifically chosen, save the history for future
- * use. */
+/** Return true iff <b>address</b> is matched by one of the entries in
+ * TrackHostExits. */
+int
+hostname_in_track_host_exits(or_options_t *options, const char *address)
+{
+  if (!options->TrackHostExits)
+    return 0;
+  SMARTLIST_FOREACH_BEGIN(options->TrackHostExits, const char *, cp) {
+    if (cp[0] == '.') { /* match end */
+      if (cp[1] == '\0' ||
+          !strcasecmpend(address, cp) ||
+          !strcasecmp(address, &cp[1]))
+        return 1;
+    } else if (strcasecmp(cp, address) == 0) {
+      return 1;
+    }
+  } SMARTLIST_FOREACH_END(cp);
+  return 0;
+}
+
+/** If an exit wasn't explicitly specified for <b>conn</b>, consider saving
+ * the exit that we *did* choose for use by future connections to
+ * <b>conn</b>'s destination.
+ */
 static void
 consider_recording_trackhost(edge_connection_t *conn, origin_circuit_t *circ)
 {
-  int found_needle = 0;
   or_options_t *options = get_options();
   size_t len;
   char *new_address;
@@ -1503,18 +1524,8 @@ consider_recording_trackhost(edge_connection_t *conn, origin_circuit_t *circ)
                               options->TrackHostExitsExpire))
     return; /* nothing to track, or already mapped */
 
-  SMARTLIST_FOREACH(options->TrackHostExits, const char *, cp, {
-    if (cp[0] == '.') { /* match end */
-      if (cp[1] == '\0' ||
-          !strcasecmpend(conn->socks_request->address, cp) ||
-          !strcasecmp(conn->socks_request->address, &cp[1]))
-          found_needle = 1;
-    } else if (strcasecmp(cp, conn->socks_request->address) == 0) {
-      found_needle = 1;
-    }
-  });
-
-  if (!found_needle || !circ->build_state->chosen_exit)
+  if (!hostname_in_track_host_exits(options, conn->socks_request->address) ||
+      !circ->build_state->chosen_exit)
     return;
 
   /* write down the fingerprint of the chosen exit, not the nickname,
diff --git a/src/or/circuituse.h b/src/or/circuituse.h
index 9f393ab378..bfeaea20dc 100644
--- a/src/or/circuituse.h
+++ b/src/or/circuituse.h
@@ -51,5 +51,7 @@ int connection_ap_handshake_attach_chosen_circuit(edge_connection_t *conn,
                                                   crypt_path_t *cpath);
 int connection_ap_handshake_attach_circuit(edge_connection_t *conn);
 
+int hostname_in_track_host_exits(or_options_t *options, const char *address);
+
 #endif
 
diff --git a/src/or/config.c b/src/or/config.c
index a7ff28f462..9c68b6fa59 100644
--- a/src/or/config.c
+++ b/src/or/config.c
@@ -1264,6 +1264,8 @@ options_act(or_options_t *old_options)
 
   /* Check for transitions that need action. */
   if (old_options) {
+    int revise_trackexithosts = 0;
+    int revise_automap_entries = 0;
     if ((options->UseEntryGuards && !old_options->UseEntryGuards) ||
         !routerset_equal(old_options->ExcludeNodes,options->ExcludeNodes) ||
         !routerset_equal(old_options->ExcludeExitNodes,
@@ -1276,9 +1278,30 @@ options_act(or_options_t *old_options)
                "excluded node lists. Abandoning previous circuits.");
       circuit_mark_all_unused_circs();
       circuit_expire_all_dirty_circs();
-      addressmap_clear_excluded_trackexithosts(options);
+      revise_trackexithosts = 1;
     }
 
+    if (!smartlist_strings_eq(old_options->TrackHostExits,
+                              options->TrackHostExits))
+      revise_trackexithosts = 1;
+
+    if (revise_trackexithosts)
+      addressmap_clear_excluded_trackexithosts(options);
+
+    if (old_options->AutomapHostsOnResolve && !options->AutomapHostsOnResolve) {
+      revise_automap_entries = 1;
+    } else if (options->AutomapHostsOnResolve) {
+      if (!smartlist_strings_eq(old_options->AutomapHostsSuffixes,
+                                options->AutomapHostsSuffixes))
+        revise_automap_entries = 1;
+      else if (!opt_streq(old_options->VirtualAddrNetwork,
+                          options->VirtualAddrNetwork))
+        revise_automap_entries = 1;
+    }
+
+    if (revise_automap_entries)
+      addressmap_clear_invalid_automaps(options);
+
 /* How long should we delay counting bridge stats after becoming a bridge?
  * We use this so we don't count people who used our bridge thinking it is
  * a relay. If you change this, don't forget to change the log message
diff --git a/src/or/connection_edge.c b/src/or/connection_edge.c
index 037920b688..7828f16386 100644
--- a/src/or/connection_edge.c
+++ b/src/or/connection_edge.c
@@ -810,7 +810,8 @@ clear_trackexithost_mappings(const char *exitname)
 }
 
 /** Remove all TRACKEXIT mappings from the addressmap for which the target
- * host is unknown or no longer allowed. */
+ * host is unknown or no longer allowed, or for which the source address
+ * is no longer in trackexithosts. */
 void
 addressmap_clear_excluded_trackexithosts(or_options_t *options)
 {
@@ -851,7 +852,8 @@ addressmap_clear_excluded_trackexithosts(or_options_t *options)
     tor_free(nodename);
     if (!ri ||
         (allow_nodes && !routerset_contains_router(allow_nodes, ri)) ||
-        routerset_contains_router(exclude_nodes, ri)) {
+        routerset_contains_router(exclude_nodes, ri) ||
+        !hostname_in_track_host_exits(options, address)) {
       /* We don't know this one, or we want to be rid of it. */
       addressmap_ent_remove(address, ent);
       MAP_DEL_CURRENT(address);
@@ -859,6 +861,49 @@ addressmap_clear_excluded_trackexithosts(or_options_t *options)
   } STRMAP_FOREACH_END;
 }
 
+/** Remove all AUTOMAP mappings from the addressmap for which the
+ * source address no longer matches AutomapHostsSuffixes, which is
+ * no longer allowed by AutomapHostsOnResolve, or for which the
+ * target address is no longer in the virtual network. */
+void
+addressmap_clear_invalid_automaps(or_options_t *options)
+{
+  int clear_all = !options->AutomapHostsOnResolve;
+  const smartlist_t *suffixes = options->AutomapHostsSuffixes;
+
+  if (!addressmap)
+    return;
+
+  if (!suffixes)
+    clear_all = 1; /* This should be impossible, but let's be sure. */
+
+  STRMAP_FOREACH_MODIFY(addressmap, src_address, addressmap_entry_t *, ent) {
+    int remove = clear_all;
+    if (ent->source != ADDRMAPSRC_AUTOMAP)
+      continue; /* not an automap mapping. */
+
+    if (!remove) {
+      int suffix_found = 0;
+      SMARTLIST_FOREACH(suffixes, const char *, suffix, {
+          if (!strcasecmpend(src_address, suffix)) {
+            suffix_found = 1;
+            break;
+          }
+      });
+      if (!suffix_found)
+        remove = 1;
+    }
+
+    if (!remove && ! address_is_in_virtual_range(ent->new_address))
+      remove = 1;
+
+    if (remove) {
+      addressmap_ent_remove(src_address, ent);
+      MAP_DEL_CURRENT(src_address);
+    }
+  } STRMAP_FOREACH_END;
+}
+
 /** Remove all entries from the addressmap that were set via the
  * configuration file or the command line. */
 void
@@ -1370,7 +1415,7 @@ addressmap_register_virtual_address(int type, char *new_address)
   log_info(LD_APP, "Registering map from %s to %s", *addrp, new_address);
   if (vent_needs_to_be_added)
     strmap_set(virtaddress_reversemap, new_address, vent);
-  addressmap_register(*addrp, new_address, 2, ADDRMAPSRC_CONTROLLER);
+  addressmap_register(*addrp, new_address, 2, ADDRMAPSRC_AUTOMAP);
 
 #if 0
   {
diff --git a/src/or/connection_edge.h b/src/or/connection_edge.h
index 70d0dd2713..8ba2fafd08 100644
--- a/src/or/connection_edge.h
+++ b/src/or/connection_edge.h
@@ -62,6 +62,7 @@ int address_is_invalid_destination(const char *address, int client);
 
 void addressmap_init(void);
 void addressmap_clear_excluded_trackexithosts(or_options_t *options);
+void addressmap_clear_invalid_automaps(or_options_t *options);
 void addressmap_clean(time_t now);
 void addressmap_clear_configured(void);
 void addressmap_clear_transient(void);
diff --git a/src/or/main.c b/src/or/main.c
index 15682d5400..d700f0e7a8 100644
--- a/src/or/main.c
+++ b/src/or/main.c
@@ -1417,7 +1417,6 @@ do_hup(void)
 
   router_reset_warnings();
   routerlist_reset_warnings();
-  addressmap_clear_transient();
   /* first, reload config variables, in case they've changed */
   if (options->ReloadTorrcOnSIGHUP) {
     /* no need to provide argc/v, they've been cached in init_from_config */
diff --git a/src/or/or.h b/src/or/or.h
index a73d98ab74..5647691550 100644
--- a/src/or/or.h
+++ b/src/or/or.h
@@ -3150,6 +3150,9 @@ typedef enum setopt_err_t {
 typedef enum {
   /** We're remapping this address because the controller told us to. */
   ADDRMAPSRC_CONTROLLER,
+  /** We're remapping this address because of an AutomapHostsOnResolve
+   * configuration. */
+  ADDRMAPSRC_AUTOMAP,
   /** We're remapping this address because our configuration (via torrc, the
    * command line, or a SETCONF command) told us to. */
   ADDRMAPSRC_TORRC,