Index: output.h
===================================================================
--- output.h	(revision 27196)
+++ output.h	(working copy)
@@ -27,6 +27,7 @@
   int scale;       /* scale for converting coordinates to fixed point */
   int projection;  /* SRS of projection */
   int append;      /* Append to existing data */
+  int allow_dups;  /* Allow duplicate data */
   int slim;        /* In slim mode */
   int cache;       /* Memory usable for cache in MB */
   struct middle_t *mid;  /* Mid storage to use */
Index: osm2pgsql.c
===================================================================
--- osm2pgsql.c	(revision 27196)
+++ osm2pgsql.c	(working copy)
@@ -127,6 +127,8 @@
     printf("\nOptions:\n");
     printf("   -a|--append\t\tAdd the OSM file into the database without removing\n");
     printf("              \t\texisting data.\n");
+    printf("   -A|--allow-dups\tDuplicate data is accepted by deleting the existing\n");
+    printf("              \t\tnode/way/relation before adding each new one.\n");
     printf("   -b|--bbox\t\tApply a bounding box filter on the imported data\n");
     printf("              \t\tMust be specified as: minlon,minlat,maxlon,maxlat\n");
     printf("              \t\te.g. --bbox -0.5,51.25,0.5,51.75\n");
@@ -300,6 +302,7 @@
 int main(int argc, char *argv[])
 {
     int append=0;
+    int allow_dups=0;
     int create=0;
     int slim=0;
     int sanitize=0;
@@ -341,6 +344,7 @@
         int c, option_index = 0;
         static struct option long_options[] = {
             {"append",   0, 0, 'a'},
+            {"allow-dups",0,0, 'A'},
             {"bbox",     1, 0, 'b'},
             {"create",   0, 0, 'c'},
             {"database", 1, 0, 'd'},
@@ -384,6 +388,7 @@
 
         switch (c) {
             case 'a': append=1;   break;
+            case 'A': allow_dups=1; break;
             case 'b': osmdata.bbox=optarg; break;
             case 'c': create=1;   break;
             case 'v': verbose=1;  break;
@@ -485,6 +490,7 @@
     options.conninfo = conninfo;
     options.prefix = prefix;
     options.append = append;
+    options.allow_dups = allow_dups;
     options.slim = slim;
     options.projection = project_getprojinfo()->srs;
     options.scale = (projection==PROJ_LATLONG)?10000000:100;
@@ -515,6 +521,8 @@
       exit(EXIT_FAILURE);
     }
 
+    osmdata.allow_dups=options.allow_dups;
+
     if (strcmp("auto", input_reader) != 0) {
       if (strcmp("libxml2", input_reader) == 0) {
         streamFile = &streamFileXML2;
Index: osmtypes.h
===================================================================
--- osmtypes.h	(revision 27196)
+++ osmtypes.h	(working copy)
@@ -42,6 +42,7 @@
   filetypes_t filetype;
   actions_t action;
   int extra_attributes;
+  int allow_dups;
 
   // Bounding box to filter imported data
   const char *bbox;
Index: parse-primitive.c
===================================================================
--- parse-primitive.c	(revision 27196)
+++ parse-primitive.c	(working copy)
@@ -111,7 +111,12 @@
     actions_t new_action = ACTION_NONE;
     char *action = extractAttribute(token, tokens, "action");
     if( action == NULL )
-        new_action = ACTION_CREATE;
+    {
+        if(osmdata->allow_dups)
+           new_action = ACTION_MODIFY;
+        else
+           new_action = ACTION_CREATE;
+    }
     else if( strcmp((char *)action, "modify") == 0 )
         new_action = ACTION_MODIFY;
     else if( strcmp((char *)action, "delete") == 0 )
@@ -136,7 +141,11 @@
         if (!strcmp(name, "osm"))
         {
             osmdata->filetype = FILETYPE_OSM;
-            osmdata->action = ACTION_CREATE;
+
+            if(osmdata->allow_dups)
+               osmdata->action = ACTION_MODIFY;
+            else
+               osmdata->action = ACTION_CREATE;
         }
         else if (!strcmp(name, "osmChange"))
         {
@@ -280,7 +289,10 @@
             realloc_members(osmdata);
     } else if (!strcmp(name, "add") ||
                !strcmp(name, "create")) {
-        osmdata->action = ACTION_MODIFY; // Turns all creates into modifies, makes it resiliant against inconsistant snapshots.
+        if(osmdata->allow_dups)
+           osmdata->action = ACTION_MODIFY;
+        else
+           osmdata->action = ACTION_CREATE;
     } else if (!strcmp(name, "modify")) {
         osmdata->action = ACTION_MODIFY;
     } else if (!strcmp(name, "delete")) {
Index: parse-xml2.c
===================================================================
--- parse-xml2.c	(revision 27196)
+++ parse-xml2.c	(working copy)
@@ -50,7 +50,12 @@
     actions_t new_action = ACTION_NONE;
     xmlChar *action = xmlTextReaderGetAttribute( reader, BAD_CAST "action" );
     if( action == NULL )
-        new_action = ACTION_CREATE;
+    {
+        if(osmdata->allow_dups)
+           new_action = ACTION_MODIFY;
+        else
+           new_action = ACTION_CREATE;
+    }
     else if( strcmp((char *)action, "modify") == 0 )
         new_action = ACTION_MODIFY;
     else if( strcmp((char *)action, "delete") == 0 )
@@ -73,7 +78,11 @@
         if (xmlStrEqual(name, BAD_CAST "osm"))
         {
             osmdata->filetype = FILETYPE_OSM;
-            osmdata->action = ACTION_CREATE;
+
+            if(osmdata->allow_dups)
+               osmdata->action = ACTION_MODIFY;
+            else
+               osmdata->action = ACTION_CREATE;
         }
         else if (xmlStrEqual(name, BAD_CAST "osmChange"))
         {
@@ -205,7 +214,10 @@
         xmlFree(xtype);
     } else if (xmlStrEqual(name, BAD_CAST "add") ||
                xmlStrEqual(name, BAD_CAST "create")) {
-        osmdata->action = ACTION_MODIFY; // Turns all creates into modifies, makes it resiliant against inconsistant snapshots.
+        if(osmdata->allow_dups)
+           osmdata->action = ACTION_MODIFY;
+        else
+           osmdata->action = ACTION_CREATE;
     } else if (xmlStrEqual(name, BAD_CAST "modify")) {
         osmdata->action = ACTION_MODIFY;
     } else if (xmlStrEqual(name, BAD_CAST "delete")) {