Index: dbmod.scm
==================================================================
--- dbmod.scm
+++ dbmod.scm
@@ -345,56 +345,61 @@
 (define (dbmod:attach-sync tables dbh destdbfile direction #!key
 			   (mode 'full)
 			   (no-update '("keys")) ;; do
 			   )
   (debug:print 0 *default-log-port* "Doing sync "direction" "destdbfile)
-  (let* ((table-names  (map car tables))
-	 (dest-exists  (file-exists? destdbfile)))
-    (assert dest-exists "FATAL: sync called with non-existant file, "destdbfile)
-    ;; attach the destdbfile
-    ;; for each table
-    ;;    insert into dest.<table> select * from src.<table> where last_update>last_update
-    ;; done
-    (debug:print 0 *default-log-port* "Attaching "destdbfile" as auxdb")
-    (sqlite3:execute dbh (conc "ATTACH '"destdbfile"' AS auxdb;"))
-    (for-each
-     (lambda (table)
-       (let* ((tbldat (alist-ref table tables equal?))
-	      (fields (map car tbldat))
-	      (fields-str (string-intersperse fields ","))
-	      (dir    (eq? direction 'todest))
-	      (fromdb (if dir "" "auxdb."))
-	      (todb   (if dir "auxdb." ""))
-	      (stmt1 (conc "INSERT OR IGNORE INTO "todb table
-			  " SELECT * FROM "fromdb table";"))
-	      (stmt2 (conc "INSERT OR REPLACE INTO "todb table
-			   " SELECT * FROM "fromdb table" WHERE "
-			   fromdb table".last_update > "
-			   todb table".last_update;"))
-	      (stmt3 (conc "INSERT OR REPLACE INTO "todb"."table
-			   " SELECT * FROM "fromdb table";"))
-	      (stmt4 (conc "DELETE FROM "todb table" WHERE "fromdb
-			   table ".last_update > "todb table".last_update;"))
-	      (stmt5 (conc "DELETE FROM "todb table";"))
-	      (stmt6 (conc "INSERT OR REPLACE INTO "todb table" ("fields-str") SELECT "fields-str" FROM "fromdb table";"))
-	      (start-ms (current-milliseconds)))
-	 ;; (if (not (has-last-update dbh table))
-	 ;;     (sqlite3:execute dbh (conc "ALTER TABLE "table" ADD COLUMN last_update INTEGER;")))
-	 ;; (if (not (has-last-update dbh (conc "auxdb."table)))
-	 ;;     (sqlite3:execute dbh (conc "ALTER TABLE auxdb."table" ADD COLUMN last_update INTEGER;")))
-	 (sqlite3:with-transaction
-	  dbh
-	  (lambda ()
-	    (sqlite3:execute dbh stmt5)
-	    ;; (sqlite3:execute dbh stmt4) ;; if it worked this would be better for incremental up
-	    ;; (sqlite3:execute dbh stmt1)
-	    (sqlite3:execute dbh stmt6)
-	    ))
-	 (debug:print 0 *default-log-port* "Synced table "table" in "(- (current-milliseconds) start-ms)"ms")
-	 ))
-     table-names)
-    (sqlite3:execute dbh "DETACH auxdb;")))
+  (if (not (sqlite3:auto-committing? dbh))
+      (debug:print 0 *default-log-port* "Skipping sync due to transaction in flight.")
+      (let* ((table-names  (map car tables))
+	     (dest-exists  (file-exists? destdbfile)))
+	(assert dest-exists "FATAL: sync called with non-existant file, "destdbfile)
+	;; attach the destdbfile
+	;; for each table
+	;;    insert into dest.<table> select * from src.<table> where last_update>last_update
+	;; done
+	(debug:print 0 *default-log-port* "Attaching "destdbfile" as auxdb")
+	(sqlite3:execute dbh (conc "ATTACH '"destdbfile"' AS auxdb;"))
+	(for-each
+	 (lambda (table)
+	   (let* ((tbldat (alist-ref table tables equal?))
+		  (fields (map car tbldat))
+		  (fields-str (string-intersperse fields ","))
+		  (dir    (eq? direction 'todest))
+		  (fromdb (if dir "" "auxdb."))
+		  (todb   (if dir "auxdb." ""))
+		  (stmt1 (conc "INSERT OR IGNORE INTO "todb table
+			       " SELECT * FROM "fromdb table";"))
+		  (stmt2 (conc "INSERT OR REPLACE INTO "todb table
+			       " SELECT * FROM "fromdb table" WHERE "
+			       fromdb table".last_update > "
+			       todb table".last_update;"))
+		  (stmt3 (conc "INSERT OR REPLACE INTO "todb"."table
+			       " SELECT * FROM "fromdb table";"))
+		  (stmt4 (conc "DELETE FROM "todb table" WHERE "fromdb
+			       table ".last_update > "todb table".last_update;"))
+		  (stmt5 (conc "DELETE FROM "todb table";"))
+		  (stmt6 (conc "INSERT OR REPLACE INTO "todb table" ("fields-str") SELECT "fields-str" FROM "fromdb table";"))
+		  (start-ms (current-milliseconds)))
+	     ;; (if (not (has-last-update dbh table))
+	     ;;     (sqlite3:execute dbh (conc "ALTER TABLE "table" ADD COLUMN last_update INTEGER;")))
+	     ;; (if (not (has-last-update dbh (conc "auxdb."table)))
+	     ;;     (sqlite3:execute dbh (conc "ALTER TABLE auxdb."table" ADD COLUMN last_update INTEGER;")))
+	     (if (sqlite3:auto-committing? dbh)
+		 (begin
+		   (sqlite3:with-transaction
+		    dbh
+		    (lambda ()
+		      (sqlite3:execute dbh stmt5)
+		      ;; (sqlite3:execute dbh stmt4) ;; if it worked this would be better for incremental up
+		      ;; (sqlite3:execute dbh stmt1)
+		      (sqlite3:execute dbh stmt6)
+		      ))
+		   (debug:print 0 *default-log-port* "Synced table "table
+				" in "(- (current-milliseconds) start-ms)"ms"))
+		 (debug:print 0 *default-log-port* "Skipping sync of table "table" due to transaction in flight."))))
+	 table-names)
+	(sqlite3:execute dbh "DETACH auxdb;"))))
 
 ;; prefix is "" or "auxdb."
 ;;
 ;; (define (dbmod:last-update-patch dbh prefix)
 ;;   (let ((