CONTRIBUTING.md: Add advice on pull requests

Add advice on pull requests and best practices in working with Github.
Minor corrections & updates.
Adjust to Github 'markdown' syntax.

Signed-off-by: Hannu Nyman <hannu.nyman@iki.fi>

1 files changed, 28 insertions, 9 deletions

diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 7c4291318e..a392ade0c2 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -1,16 +1,16 @@
 # Contributing Guidelines
 
-Patches and pull-requests:
+## Patches and Pull requests:
 
 If you want to contribute a change to LuCI, please either send a patch using git send-email
-or open a pull request against the openwrt/luci repository.
+or open a "pull request" against the openwrt/luci repository.
 
 Regardless of whether you send a patch or open a pull request, please try to follow these rules:
 
-* Have a useful subject prefixed with the component name  
-    (E.g.: "modules/admin-full: fix wifi channel selection on multiple STA networks")
+* Have a useful subject prefixed with the component name
+    (E.g.: "luci-mod-admin-full: fix wifi channel selection on multiple STA networks")
 * Shortly explain the changes made and - if applicable - the reasoning behind them
-* Include Signed-off-by in the comment  
+* Include Signed-off-by in the comment
     (See <https://dev.openwrt.org/wiki/SubmittingPatches#a10.Signyourwork>)
 	
 In case you like to send patches by mail, please use the [LuCI mailinglist](https://lists.subsignal.org/mailman/listinfo/luci)
@@ -19,22 +19,41 @@ or the [OpenWrt Development List](https://lists.openwrt.org/cgi-bin/mailman/list
 If you send via the OpenWrt list, include a "[luci]" tag in your subject line.
 For general information on patch submission, follow the [OpenWrt patch submission guideline](https://dev.openwrt.org/wiki/SubmittingPatches).
 
+## Advice on pull requests:
 
-If you have commit access:
+Pull requests are the easiest way to contribute changes to git repos at Github. They are the preferred contribution method, as they offer a nice way for commenting and amending the proposed changes.
+
+* You need a local "fork" of the Github repo.
+* Use a "feature branch" for your changes. That separates the changes in the pull request from your other changes and makes it easy to edit/amend commits in the pull request. Workflow using "feature_x" as the example:
+  - Update your local git fork to the tip (of the master, usually)
+  - Create the feature branch with `git checkout -b feature_x`
+  - Edit changes and commit them locally
+  - Push them to your Github fork by `git push -u origin feature_x`. That creates the "feature_x" branch at your Github fork and sets it as the remote of this branch
+  - When you now visit Github, you should see a proposal to create a pull request
+
+* If you later need to add new commits to the pull request, you can simply commit the changes to the local branch and then use `git push` to automatically update the pull request.
+
+* If you need to change something in the existing pull request (e.g. to add a missing signed-off-by line to the commit message), you can use `git push -f` to overwrite the original commits. That is easy and safe when using a feature branch. Example workflow:
+  - Checkout the feature branch by `git checkout feature_x`
+  - Edit changes and commit them locally. If you are just updating the commit message in the last commit, you can use `git commit --amend` to do that
+  - If you added several new commits or made other changes that require cleaning up, you can use `git rebase -i HEAD~X` (X = number of commits to edit) to possibly squash some commits
+  - Push the changed commits to Github with `git push -f` to overwrite the original commits in the "feature_x" branch with the new ones. The pull request gets automatically updated
+
+## If you have commit access:
 
 * Do NOT use git push --force.
 * Use Pull Requests if you are unsure and to suggest changes to other developers.
 
-Gaining commit access:
+## Gaining commit access:
 
 * Commit access will be granted to responsible contributors who have made
   useful pull requests and / or feedback or patches to this repository or
   OpenWrt in general. Please include your request for commit access in your
   next pull request or ticket.
 
-Release Branches:
+## Release Branches:
 
-* Branches named "luci-X.Y" (e.g. luci-0.12) are release branches.
+* Branches named "for-XX.YY" or "luci-X.Y" (e.g. "for-15.05") are release branches.
 * These branches are built with the respective OpenWrt release and are created
   during the release stabilisation phase.
 * Please ONLY cherry-pick or commit security and bug-fixes to these branches.