From c5993ecb8121ccbdc23042b72ceddc74205f9294 Mon Sep 17 00:00:00 2001
From: Oliver Tonnhofer <olt@bogosoft.com>
Date: Tue, 6 Dec 2016 10:49:17 +0100
Subject: [PATCH] only set DiffElem.Mod to true on modify

---
 diff/deleter.go       |  2 +-
 diff/parser/parser.go |  4 ++--
 diff/process.go       | 45 +++++++++++++++++++++----------------------
 3 files changed, 25 insertions(+), 26 deletions(-)

diff --git a/diff/deleter.go b/diff/deleter.go
index 377a2da..bf8d0a5 100644
--- a/diff/deleter.go
+++ b/diff/deleter.go
@@ -271,7 +271,7 @@ func (d *Deleter) Delete(delElem parser.DiffElem) error {
 				}
 			}
 		}
-		if !delElem.Add {
+		if delElem.Del {
 			if err := d.diffCache.Coords.Delete(delElem.Node.Id); err != nil {
 				return err
 			}
diff --git a/diff/parser/parser.go b/diff/parser/parser.go
index 451cccb..53cf4e6 100644
--- a/diff/parser/parser.go
+++ b/diff/parser/parser.go
@@ -73,9 +73,9 @@ NextToken:
 				mod = false
 				del = false
 			case "modify":
-				add = true
+				add = false
 				mod = true
-				del = true
+				del = false
 			case "delete":
 				add = false
 				mod = false
diff --git a/diff/process.go b/diff/process.go
index 60680df..cb57c44 100644
--- a/diff/process.go
+++ b/diff/process.go
@@ -223,35 +223,34 @@ func Update(oscFile string, geometryLimiter *limit.Limiter, expireor expire.Expi
 				return diffError(err, "delete element %#v", elem)
 			}
 			if elem.Del {
-				if !elem.Add {
-					// no new or modified elem -> remove from cache
-					if elem.Rel != nil {
-						if err := osmCache.Relations.DeleteRelation(elem.Rel.Id); err != nil && err != cache.NotFound {
-							return diffError(err, "delete relation %v", elem.Rel)
-						}
-					} else if elem.Way != nil {
-						if err := osmCache.Ways.DeleteWay(elem.Way.Id); err != nil && err != cache.NotFound {
-							return diffError(err, "delete way %v", elem.Way)
-						}
-						if err := diffCache.Ways.Delete(elem.Way.Id); err != nil && err != cache.NotFound {
-							return diffError(err, "delete way references %v", elem.Way)
-						}
-					} else if elem.Node != nil {
-						if err := osmCache.Nodes.DeleteNode(elem.Node.Id); err != nil && err != cache.NotFound {
-							return diffError(err, "delete node %v", elem.Node)
-						}
-						if err := osmCache.Coords.DeleteCoord(elem.Node.Id); err != nil && err != cache.NotFound {
-							return diffError(err, "delete coord %v", elem.Node)
-						}
+				// no new or modified elem -> remove from cache
+				if elem.Rel != nil {
+					if err := osmCache.Relations.DeleteRelation(elem.Rel.Id); err != nil && err != cache.NotFound {
+						return diffError(err, "delete relation %v", elem.Rel)
 					}
-				} else if elem.Node != nil && elem.Node.Tags == nil {
-					// handle modifies where a node drops all tags
+				} else if elem.Way != nil {
+					if err := osmCache.Ways.DeleteWay(elem.Way.Id); err != nil && err != cache.NotFound {
+						return diffError(err, "delete way %v", elem.Way)
+					}
+					if err := diffCache.Ways.Delete(elem.Way.Id); err != nil && err != cache.NotFound {
+						return diffError(err, "delete way references %v", elem.Way)
+					}
+				} else if elem.Node != nil {
 					if err := osmCache.Nodes.DeleteNode(elem.Node.Id); err != nil && err != cache.NotFound {
 						return diffError(err, "delete node %v", elem.Node)
 					}
+					if err := osmCache.Coords.DeleteCoord(elem.Node.Id); err != nil && err != cache.NotFound {
+						return diffError(err, "delete coord %v", elem.Node)
+					}
 				}
 			}
-			if elem.Add {
+			if elem.Mod && elem.Node != nil && elem.Node.Tags == nil {
+				// handle modifies where a node drops all tags
+				if err := osmCache.Nodes.DeleteNode(elem.Node.Id); err != nil && err != cache.NotFound {
+					return diffError(err, "delete node %v", elem.Node)
+				}
+			}
+			if elem.Add || elem.Mod {
 				if elem.Rel != nil {
 					// check if first member is cached to avoid caching
 					// unneeded relations (typical outside of our coverage)