From 7719117e1e1b0d4d7b1d3740329cbea92258c6f8 Mon Sep 17 00:00:00 2001
From: webzwo0i <webzwo0i@c3d2.de>
Date: Thu, 26 Feb 2015 14:57:49 +0100
Subject: [PATCH 1/3] do not crash when encountering mismatched compositions.
 log the changesets and padid

---
 src/node/handler/PadMessageHandler.js | 12 ++++++++----
 src/static/js/Changeset.js            |  2 +-
 2 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/src/node/handler/PadMessageHandler.js b/src/node/handler/PadMessageHandler.js
index 7ea5039d8..86244d85d 100644
--- a/src/node/handler/PadMessageHandler.js
+++ b/src/node/handler/PadMessageHandler.js
@@ -1629,10 +1629,14 @@ function composePadChangesets(padId, startNum, endNum, callback)
       changeset = changesets[startNum];
       var pool = pad.apool();
 
-      for(var r=startNum+1;r<endNum;r++)
-      {
-        var cs = changesets[r];
-        changeset = Changeset.compose(changeset, cs, pool);
+      try {
+        for(var r=startNum+1;r<endNum;r++) {
+          var cs = changesets[r];
+          changeset = Changeset.compose(changeset, cs, pool);
+        }
+      } catch(e){
+        console.warn("failed to compose cs in pad:",padId);
+        return;
       }
 
       callback(null);
diff --git a/src/static/js/Changeset.js b/src/static/js/Changeset.js
index df180f9cf..c97756b8d 100644
--- a/src/static/js/Changeset.js
+++ b/src/static/js/Changeset.js
@@ -1318,7 +1318,7 @@ exports.compose = function (cs1, cs2, pool) {
   var unpacked2 = exports.unpack(cs2);
   var len1 = unpacked1.oldLen;
   var len2 = unpacked1.newLen;
-  exports.assert(len2 == unpacked2.oldLen, "mismatched composition of two changesets");
+  exports.assert(len2 == unpacked2.oldLen, "mismatched composition of two changesets - cs1:",cs1," and cs2:",cs2);
   var len3 = unpacked2.newLen;
   var bankIter1 = exports.stringIterator(unpacked1.charBank);
   var bankIter2 = exports.stringIterator(unpacked2.charBank);

From 683c9dfb7cc01ef46d6f783102c6acb4b32255dd Mon Sep 17 00:00:00 2001
From: webzwo0i <webzwo0i@c3d2.de>
Date: Mon, 2 Mar 2015 11:05:33 +0100
Subject: [PATCH 2/3] callback with argument error in async.series instead

---
 src/node/handler/PadMessageHandler.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/node/handler/PadMessageHandler.js b/src/node/handler/PadMessageHandler.js
index 86244d85d..e585b6528 100644
--- a/src/node/handler/PadMessageHandler.js
+++ b/src/node/handler/PadMessageHandler.js
@@ -1636,7 +1636,7 @@ function composePadChangesets(padId, startNum, endNum, callback)
         }
       } catch(e){
         console.warn("failed to compose cs in pad:",padId);
-        return;
+        return callback(e);
       }
 
       callback(null);

From 0f82cd871141a4ca465e171dd4eb0fe6a73058f6 Mon Sep 17 00:00:00 2001
From: webzwo0i <webzwo0i@c3d2.de>
Date: Mon, 2 Mar 2015 11:14:24 +0100
Subject: [PATCH 3/3] print revision numbers - not changesets - in warn-log

---
 src/node/handler/PadMessageHandler.js | 3 ++-
 src/static/js/Changeset.js            | 2 +-
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/node/handler/PadMessageHandler.js b/src/node/handler/PadMessageHandler.js
index e585b6528..ac8904f8d 100644
--- a/src/node/handler/PadMessageHandler.js
+++ b/src/node/handler/PadMessageHandler.js
@@ -1635,7 +1635,8 @@ function composePadChangesets(padId, startNum, endNum, callback)
           changeset = Changeset.compose(changeset, cs, pool);
         }
       } catch(e){
-        console.warn("failed to compose cs in pad:",padId);
+        // r-1 indicates the rev that was build starting with startNum, applying startNum+1, +2, +3
+        console.warn("failed to compose cs in pad:",padId," startrev:",startNum," current rev:",r);
         return callback(e);
       }
 
diff --git a/src/static/js/Changeset.js b/src/static/js/Changeset.js
index c97756b8d..df180f9cf 100644
--- a/src/static/js/Changeset.js
+++ b/src/static/js/Changeset.js
@@ -1318,7 +1318,7 @@ exports.compose = function (cs1, cs2, pool) {
   var unpacked2 = exports.unpack(cs2);
   var len1 = unpacked1.oldLen;
   var len2 = unpacked1.newLen;
-  exports.assert(len2 == unpacked2.oldLen, "mismatched composition of two changesets - cs1:",cs1," and cs2:",cs2);
+  exports.assert(len2 == unpacked2.oldLen, "mismatched composition of two changesets");
   var len3 = unpacked2.newLen;
   var bankIter1 = exports.stringIterator(unpacked1.charBank);
   var bankIter2 = exports.stringIterator(unpacked2.charBank);