From fbb6847985cd61b0d96c8695734e7c1d8ea53b47 Mon Sep 17 00:00:00 2001
From: Pierre-Yves Chibon <pingou@pingoured.fr>
Date: Mar 29 2017 11:24:10 +0000
Subject: Fix generating the diff of two branches


Until now the algorithm was looking at the main branch and the feature
branch and for each step in both branches checking if there was a shared
commit.
Otherwise it would keep the list of the commits seen.
The first time it finds a shared commit, it stops.

Then we clear from the list of diff commits all the ones found in master.
Except that we may end up in a situation where we have in the diff list
a number of commits that are already in master but after the first one
shared.
Say:
a - b - c - d - e - f - g
      \ h
The diff list would be [h, b, a  ...] since it will take some iteration
to reach the b commit on both branches.

With this commit, instead of removing all the commits that are in master
it iterates through the list of diff commits and only keep the commit
that are present before the first shared commit.

---

diff --git a/pagure/internal/__init__.py b/pagure/internal/__init__.py
index 0a3bca2..d76b7b8 100644
--- a/pagure/internal/__init__.py
+++ b/pagure/internal/__init__.py
@@ -296,7 +296,7 @@ def get_pull_request_ready_branch():
                 if compare_branch:
                     try:
                         com = main_walker.next()
-                        main_commits.add(com.hex)
+                        main_commits.add(com.oid.hex)
                     except StopIteration:
                         com = None
                 try:
@@ -309,22 +309,17 @@ def get_pull_request_ready_branch():
                     break
 
                 if branch_commit:
-                    tmp = set(branch_commits + [branch_commit.hex])
-                else:
-                    tmp = set(branch_commits)
-                if main_commits.intersection(tmp):
-                    break
-
-                if branch_commit:
                     branch_commits.append(branch_commit.hex)
+                if main_commits.intersection(set(branch_commits)):
+                    break
 
             # If master is ahead of branch, we need to remove the commits
-            # that are already in master
-            branch_commits = [
-                com
-                for com in branch_commits
-                if com not in main_commits
-            ]
+            # that are after the first one found in master
+            i = 0
+            for i in range(len(branch_commits)):
+                if branch_commits[i] in main_commits:
+                    break
+            branch_commits = branch_commits[:i]
 
             if branch_commits:
                 branches[branchname] = branch_commits
diff --git a/pagure/lib/git.py b/pagure/lib/git.py
index e177772..8a9b118 100644
--- a/pagure/lib/git.py
+++ b/pagure/lib/git.py
@@ -1377,7 +1377,7 @@ def diff_pull_request(
         while 1:
             try:
                 com = main_walker.next()
-                main_commits.add(com.hex)
+                main_commits.add(com.oid.hex)
             except StopIteration:
                 com = None
 
@@ -1392,19 +1392,17 @@ def diff_pull_request(
 
             if branch_commit:
                 branch_commits.add(branch_commit.oid.hex)
+                diff_commits.append(branch_commit)
             if main_commits.intersection(branch_commits):
                 break
 
-            if branch_commit:
-                diff_commits.append(branch_commit)
-
         # If master is ahead of branch, we need to remove the commits
-        # that are already in master
-        diff_commits = [
-            com
-            for com in diff_commits
-            if com.oid.hex not in main_commits
-        ]
+        # that are after the first one found in master
+        i = 0
+        for i in range(len(diff_commits)):
+            if diff_commits[i].oid.hex in main_commits:
+                break
+        diff_commits = diff_commits[:i]
 
         if request.status and diff_commits:
             first_commit = repo_obj[diff_commits[-1].oid.hex]
diff --git a/pagure/ui/fork.py b/pagure/ui/fork.py
index 8338e93..75d4818 100644
--- a/pagure/ui/fork.py
+++ b/pagure/ui/fork.py
@@ -96,7 +96,7 @@ def _get_pr_info(repo_obj, orig_repo, branch_from, branch_to):
         while 1:
             try:
                 com = main_walker.next()
-                main_commits.add(com.hex)
+                main_commits.add(com.oid.hex)
             except StopIteration:
                 com = None
 
@@ -111,19 +111,17 @@ def _get_pr_info(repo_obj, orig_repo, branch_from, branch_to):
 
             if branch_commit:
                 branch_commits.add(branch_commit.oid.hex)
+                diff_commits.append(branch_commit)
             if main_commits.intersection(branch_commits):
                 break
 
-            if branch_commit:
-                diff_commits.append(branch_commit)
-
         # If master is ahead of branch, we need to remove the commits
-        # that are already in master
-        diff_commits = [
-            com
-            for com in diff_commits
-            if com.oid.hex not in main_commits
-        ]
+        # that are after the first one found in master
+        i = 0
+        for i in range(len(diff_commits)):
+            if diff_commits[i].oid.hex in main_commits:
+                break
+        diff_commits = diff_commits[:i]
 
         if diff_commits:
             first_commit = repo_obj[diff_commits[-1].oid.hex]