Work in progress. Add fetch part of pull

* R/pull.r: Work in progress with pull.

* tests/pull.R: Initial work with pull test case.

Signed-off-by: Stefan Widgren <stefan.widgren@gmail.com>
Don't run failing pull test case (yet)

Signed-off-by: Stefan Widgren <stefan.widgren@gmail.com>
Add internal function to perform a fast-forward merge

* src/git2r_merge.c (git2r_fast_forward_merge): Add function to
  perform a fast-forward merge.

Signed-off-by: Stefan Widgren <stefan.widgren@gmail.com>
Add missing include file

* src/git2r_merge.c: Include 'buffer.h'

Signed-off-by: Stefan Widgren <stefan.widgren@gmail.com>
Add method to merge branch into HEAD

* r/merge.r: Add generic merge and method for git_branch to merge the
  branch into HEAD.

* man/merge-methods.Rd: Add documentation

* NAMESPACE: Update to export merge

Signed-off-by: Stefan Widgren <stefan.widgren@gmail.com>
Add internal function to perform a normal merge

* src/git2r_merge.c (git2r_normal_merge): Add function to merge the
  given commit(s) into HEAD.

Signed-off-by: Stefan Widgren <stefan.widgren@gmail.com>
Fix broken build

* src/git2r_merge.c (git2r_normal_merge): Add argument ‘merge_opts’ to
  fix undeclared error.

Signed-off-by: Stefan Widgren <stefan.widgren@gmail.com>
Add internal function to handle merge logic

* src/git2r_merge.c (git2r_merge): Internal function to handle the
  merge logic with merge analysis and merge using normal merge or
  fast-forward merge.

Signed-off-by: Stefan Widgren <stefan.widgren@gmail.com>
Add S4 class git_merge_result

* R/S4_classes.r (git_merge_result): Return result from merge with
  class.

* man/git_merge_result.Rd: Add documentation.

Signed-off-by: Stefan Widgren <stefan.widgren@gmail.com>
Update NAMESPACE

Signed-off-by: Stefan Widgren <stefan.widgren@gmail.com>
Minor fix documentation

Signed-off-by: Stefan Widgren <stefan.widgren@gmail.com>
Add argument commit_on_success to merge branch

* R/merge.r: If there are no conflicts written to the index, the merge
  commit will be committed. Default is TRUE.

* man/merge-methods.Rd: Update documentation

Signed-off-by: Stefan Widgren <stefan.widgren@gmail.com>
Handle merge result in fast-forward merge

Signed-off-by: Stefan Widgren <stefan.widgren@gmail.com>
Add argument to handle checkout options in normal merge

Signed-off-by: Stefan Widgren <stefan.widgren@gmail.com>
Update merge function to handle merge result and checkout options

Signed-off-by: Stefan Widgren <stefan.widgren@gmail.com>
Add internal function to free memory of merge_heads

* src/git2r_merge.c (git2r_merge_heads_free): Free each git_merge_head
  in merge_heads and free memory of merge_heads.

Signed-off-by: Stefan Widgren <stefan.widgren@gmail.com>
Add internal function to merge branch into HEAD

* src/git2r_merge.c (git2r_merge_branch): Add function.

Signed-off-by: Stefan Widgren <stefan.widgren@gmail.com>
Fix typo in documentation

Signed-off-by: Stefan Widgren <stefan.widgren@gmail.com>
Update callMethods

* src/git2r.c: Add 'git2r_merge_branch' to callMethods

Signed-off-by: Stefan Widgren <stefan.widgren@gmail.com>
Add fast-forward merge test case

* tests/fast_forward_merge.R: Add test case

Signed-off-by: Stefan Widgren <stefan.widgren@gmail.com>