[PATCH v3 0/3] git-p4: Search for parent commit on branch creation

@@ -1975,7 +1975,7 @@ class P4Sync(Command, P4UserMap):
     def importChanges(self, changes):
         cnt = 1
         for change in changes:
-            description = p4Cmd("describe %s" % change)
+            description = p4Cmd(["describe", str(change)])
             self.updateOptionDict(description)
 
             if not self.silent:

@@ -1429,6 +1429,8 @@ class P4Sync(Command, P4UserMap):
         self.cloneExclude = []
         self.useClientSpec = False
         self.clientSpecDirs = None
+        self.tempBranches = []
+        self.tempBranchLocation = "git-p4-tmp"
 
         if gitConfig("git-p4.syncFromOrigin") == "false":
             self.syncWithOrigin = False

@@ -1450,6 +1452,14 @@ class P4Sync(Command, P4UserMap):
                    .replace("%25", "%")
         return path
 
+    # Force a checkpoint in fast-import and wait for it to finish
+    def checkpoint(self):
+        self.gitStream.write("checkpoint\n\n")
+        self.gitStream.write("progress checkpoint\n\n")
+        out = self.gitOutput.readline()
+        if self.verbose:
+            print "checkpoint finished: " + out
+
     def extractFilesFromCommit(self, commit):
         self.cloneExclude = [re.sub(r"\.\.\.$", "", path)
                              for path in self.cloneExclude]

@@ -1948,6 +1958,20 @@ class P4Sync(Command, P4UserMap):
         self.importChanges(changes)
         return True
 
+    def searchParent(self, parent, branch, target):
+        parentFound = False
+        for blob in read_pipe_lines(["git", "rev-list", "--reverse", "--no-merges", parent]):
+            blob = blob.strip()
+            if len(read_pipe(["git", "diff-tree", blob, target])) == 0:
+                parentFound = True
+                if self.verbose:
+                    print "Found parent of %s in commit %s" % (branch, blob)
+                break
+        if parentFound:
+            return blob
+        else:
+            return None
+
     def importChanges(self, changes):
         cnt = 1
         for change in changes:

@@ -2004,7 +2028,21 @@ class P4Sync(Command, P4UserMap):
                             parent = self.initialParents[branch]
                             del self.initialParents[branch]
 
-                        self.commit(description, filesForCommit, branch, [branchPrefix], parent)
+                        blob = None
+                        if len(parent) > 0:
+                            tempBranch = os.path.join(self.tempBranchLocation, "%d" % (change))
+                            if self.verbose:
+                                print "Creating temporary branch: " + tempBranch
+                            self.commit(description, filesForCommit, tempBranch, [branchPrefix])
+                            self.tempBranches.append(tempBranch)
+                            self.checkpoint()
+                            blob = self.searchParent(parent, branch, tempBranch)
+                        if blob:
+                            self.commit(description, filesForCommit, branch, [branchPrefix], blob)
+                        else:
+                            if self.verbose:
+                                print "Parent of %s not found. Committing into head of %s" % (branch, parent)
+                            self.commit(description, filesForCommit, branch, [branchPrefix], parent)
                 else:
                     files = self.extractFilesFromCommit(description)
                     self.commit(description, files, self.branch, self.depotPaths,

@@ -2339,6 +2377,12 @@ class P4Sync(Command, P4UserMap):
         self.gitOutput.close()
         self.gitError.close()
 
+        # Cleanup temporary branches created during import
+        if self.tempBranches != []:
+            for branch in self.tempBranches:
+                read_pipe("git update-ref -d %s" % branch)
+            os.rmdir(os.path.join(os.environ.get("GIT_DIR", ".git"), self.tempBranchLocation))
+
         return True
 
 class P4Rebase(Command):

@@ -172,9 +172,9 @@ test_expect_success 'add simple p4 branches' '
 		echo file1 >file1 &&
 		echo file2 >file2 &&
 		p4 add file1 file2 &&
-		p4 submit -d "branch1" &&
+		p4 submit -d "Create branch1" &&
 		p4 integrate //depot/branch1/... //depot/branch2/... &&
-		p4 submit -d "branch2" &&
+		p4 submit -d "Integrate branch2 from branch1" &&
 		echo file3 >file3 &&
 		p4 add file3 &&
 		p4 submit -d "add file3 in branch1" &&

@@ -182,7 +182,7 @@ test_expect_success 'add simple p4 branches' '
 		echo update >>file2 &&
 		p4 submit -d "update file2 in branch1" &&
 		p4 integrate //depot/branch1/... //depot/branch3/... &&
-		p4 submit -d "branch3"
+		p4 submit -d "Integrate branch3 from branch1"
 	)
 '
 

@@ -203,17 +203,17 @@ test_expect_success 'git-p4 clone simple branches' '
 		test -f file1 &&
 		test -f file2 &&
 		test -f file3 &&
-		grep -q update file2 &&
+		grep update file2 &&
 		git reset --hard p4/depot/branch2 &&
 		test -f file1 &&
 		test -f file2 &&
 		test ! -f file3 &&
-		test_must_fail grep -q update file2 &&
+		test_must_fail grep update file2 &&
 		git reset --hard p4/depot/branch3 &&
 		test -f file1 &&
 		test -f file2 &&
 		test -f file3 &&
-		grep -q update file2 &&
+		grep update file2 &&
 		cd "$cli" &&
 		cd branch1 &&
 		p4 edit file2 &&

@@ -222,7 +222,87 @@ test_expect_success 'git-p4 clone simple branches' '
 		cd "$git" &&
 		git reset --hard p4/depot/branch1 &&
 		"$GITP4" rebase &&
-		grep -q file2_ file2
+		grep file2_ file2
+	)
+'
+
+# Create a complex branch structure in P4 depot to check if they are correctly
+# cloned. The branches are created from older changelists to check if git-p4 is
+# able to correctly detect them.
+# The final expected structure is:
+# `branch1
+# | `- file1
+# | `- file2 (updated)
+# | `- file3
+# `branch2
+# | `- file1
+# | `- file2
+# `branch3
+# | `- file1
+# | `- file2 (updated)
+# | `- file3
+# `branch4
+# | `- file1
+# | `- file2
+# `branch5
+#   `- file1
+#   `- file2
+#   `- file3
+test_expect_success 'git-p4 add complex branches' '
+	test_when_finished cleanup_git &&
+	test_create_repo "$git" &&
+	(
+		cd "$cli" &&
+		changelist=$(p4 changes -m1 //depot/... | cut -d" " -f2) &&
+		changelist=$(($changelist - 5)) &&
+		p4 integrate //depot/branch1/...@$changelist //depot/branch4/... &&
+		p4 submit -d "Integrate branch4 from branch1@${changelist}" &&
+		changelist=$(($changelist + 2)) &&
+		p4 integrate //depot/branch1/...@$changelist //depot/branch5/... &&
+		p4 submit -d "Integrate branch5 from branch1@${changelist}"
+	)
+'
+
+# Configure branches through git-config and clone them. git-p4 will only be able
+# to clone the original structure if it is able to detect the origin changelist
+# of each branch.
+test_expect_success 'git-p4 clone complex branches' '
+	test_when_finished cleanup_git &&
+	test_create_repo "$git" &&
+	(
+		cd "$git" &&
+		git config git-p4.branchList branch1:branch2 &&
+		git config --add git-p4.branchList branch1:branch3 &&
+		git config --add git-p4.branchList branch1:branch4 &&
+		git config --add git-p4.branchList branch1:branch5 &&
+		"$GITP4" clone --dest=. --detect-branches //depot@all &&
+		git log --all --graph --decorate --stat &&
+		git reset --hard p4/depot/branch1 &&
+		test_path_is_file file1 &&
+		test_path_is_file file2 &&
+		test_path_is_file file3 &&
+		grep update file2 &&
+		git reset --hard p4/depot/branch2 &&
+		test_path_is_file file1 &&
+		test_path_is_file file2 &&
+		test_path_is_missing file3 &&
+		test_must_fail grep update file2 &&
+		git reset --hard p4/depot/branch3 &&
+		test_path_is_file file1 &&
+		test_path_is_file file2 &&
+		test_path_is_file file3 &&
+		grep update file2 &&
+		git reset --hard p4/depot/branch4 &&
+		test_path_is_file file1 &&
+		test_path_is_file file2 &&
+		test_path_is_missing file3 &&
+		test_must_fail grep update file2 &&
+		git reset --hard p4/depot/branch5 &&
+		test_path_is_file file1 &&
+		test_path_is_file file2 &&
+		test_path_is_file file3 &&
+		test_must_fail grep update file2 &&
+		test_path_is_missing .git/git-p4-tmp
 	)
 '