Refactor and improve git squash

`git squash` refactor:
- first argument can be a branch or a commit reference
- the `--me` argument is not required anymore
- use `git reset --soft` is squashing on a current branch
- if squashing on master branch, prompt for confirmation
- does not delete provided branch after squashing
- fix bug: if `git merge --squash` command fails, exit script

Update README and man pages.

Fixes #95
Closes #198

Readme.md

@@ -505,13 +505,20 @@ $ git graft new_feature dev
 $ git graft new_feature
 ```
 
-## git-squash <src-branch> [msg]
+## git-squash <src-branch|commit ref> [msg]
 
-Merge commits from `src-branch` into the current branch as a _single_ commit. When `[msg]` is given `git-commit(1)` will be invoked with that message. This is useful when small individual commits within a topic branch are irrelevant and you want to consider the topic as a single change.
+Merge commits from `src-branch` into the current branch as a _single_ commit.
+Also works if a commit reference from the current branch is provided.
+When `[msg]` is given `git-commit(1)` will be invoked with that message. This is
+useful when small individual commits within a topic branch are irrelevant and
+you want to consider the topic as a single change.
 
 ```bash
 $ git squash fixed-cursor-styling
 $ git squash fixed-cursor-styling "Fixed cursor styling"
+$ git squash 95b7c52
+$ git squash HEAD~3
+$ git squash HEAD~3 "Work on a feature"
 ```
 
 ## git-changelog

bin/git-squash

@@ -1,38 +1,53 @@
-#!/bin/sh
+#!/bin/bash
 
-src=$1
-msg=$2
+src="$1"
+msg="$2"
 
-test -z $src && echo "source branch required, or use --me." && exit 1
+is_branch() {
+  git show-ref --verify --quiet "refs/heads/$src"
+}
 
-# squash current branch
-# TODO: do this in a less hacky way
-# TODO: less sketchy arguments
+is_commit_reference() {
+  git rev-parse --verify --quiet "$src" > /dev/null 2>&1
+}
 
-if [[ $1 == "--me" ]]; then
-  msg=$3
-  branch=`git rev-parse --abbrev-ref HEAD`
-
-  # merge against target branch or master
-  git checkout ${2-master}
-
-  git checkout -B squash-tmp
-  git squash $branch
-  git branch -D $branch
-  git checkout -B $branch
-  git branch -D squash-tmp
+is_on_current_branch() {
+  local commit_sha=`git rev-parse "$src"`
+  git rev-list HEAD |
+    grep -q "$commit_sha"
+}
 
+commit_if_msg_provided() {
   if test -n "$msg"; then
     git commit -a -m "$msg"
   fi
-
-  exit
-fi
-
-# squash $src
-
-git merge --squash $src
-
-if test -n "$msg"; then
-  git commit -a -m "$msg" && git branch -D $src
+}
+
+prompt_continuation_if_squashing_master() {
+  if [[ $src =~ ^master$ ]]; then
+    read -p "Warning: squashing '$src'! Continue [y/N]? " -r
+    if ! [[ $REPLY =~ ^[Yy]$ ]]; then
+      echo "Exiting"
+      exit 1
+    fi
+  fi
+}
+
+squash_branch() {
+  prompt_continuation_if_squashing_master
+  git merge --squash "$src" || exit 1  # quits if `git merge` fails
+  commit_if_msg_provided
+}
+
+squash_current_branch() {
+  git reset --soft "$src" || exit 1    # quits if `git reset` fails
+  commit_if_msg_provided
+}
+
+if `is_branch`; then
+  squash_branch
+elif `is_commit_reference` && `is_on_current_branch`; then
+  squash_current_branch
+else
+  echo "Source branch or commit reference required." 1>&2 && exit 1
 fi

man/git-squash.1

@@ -1,13 +1,13 @@
 .\" generated with Ronn/v0.7.3
-.\" https://github.com/rtomayko/ronn/tree/0.7.3
+.\" http://github.com/rtomayko/ronn/tree/0.7.3
 .
-.TH "GIT\-SQUASH" "1" "July 2012" "" ""
+.TH "GIT\-SQUASH" "1" "July 2014" "" ""
 .
 .SH "NAME"
-\fBgit\-squash\fR \- Import changes from a branch
+\fBgit\-squash\fR \- Import changes form a branch
 .
 .SH "SYNOPSIS"
-\fBgit\-squash\fR <source\-branch> [<commit\-message>]
+\fBgit\-squash\fR <source\-branch|commit ref> [<commit\-message>]
 .
 .SH "DESCRIPTION"
 Produce the working tree and index state as if a real merge happened without the commit or merge marks\.
@@ -19,6 +19,9 @@ Produce the working tree and index state as if a real merge happened without the
 Branch to squash on the actual branch\.
 .
 .P
+<commit reference> A commit reference (has to be from the current branch) can also be used as the first argument\. A range of commits \fIsha\fR\.\.HEAD will be squashed\.
+.
+.P
 <commit\-message>
 .
 .P
@@ -35,14 +38,16 @@ Squash commit \-\- not updating HEAD
  my\-changed\-file | 1 +
  1 file changed, 1 insertion(+)
 $ git commit \-m "New commit without a real merge"
+
+$ git squash HEAD~3 "Commit message"
 .
 .fi
 .
 .SH "AUTHOR"
 Written by Jesús Espino <\fIjespinog@gmail\.com\fR>
 .
 .SH "REPORTING BUGS"
-<\fIhttp://github\.com/visionmedia/git\-extras/issues\fR>
+<\fIhttps://github\.com/visionmedia/git\-extras/issues\fR>
 .
 .SH "SEE ALSO"
-<\fIhttp://github\.com/visionmedia/git\-extras\fR>
+<\fIhttps://github\.com/visionmedia/git\-extras\fR>

man/git-squash.md

@@ -3,7 +3,7 @@ git-squash(1) -- Import changes form a branch
 
 ## SYNOPSIS
 
-`git-squash` <source-branch> [<commit-message>] 
+`git-squash` <source-branch|commit ref> [<commit-message>]
 
 ## DESCRIPTION
 
@@ -16,6 +16,10 @@ git-squash(1) -- Import changes form a branch
 
   Branch to squash on the actual branch.
 
+  <commit reference>
+  A commit reference (has to be from the current branch) can also be used as the
+  first argument. A range of commits <sha>..HEAD will be squashed.
+
   &lt;commit-message&gt;
 
   If commit-message is given, commit the squash result and delete the source-branch.
@@ -30,6 +34,8 @@ git-squash(1) -- Import changes form a branch
      1 file changed, 1 insertion(+)
     $ git commit -m "New commit without a real merge"
 
+    $ git squash HEAD~3 "Commit message"
+
 ## AUTHOR
 
 Written by Jesús Espino &lt;<jespinog@gmail.com>&gt;