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[PATCHv5 1/2] bash completion: Support "divergence from upstream" messages in __git_ps1

From
ASAndrew Sayers <andrew-git@pileofstuff.org>
Date
Jun 17, 2010, 21:32 UTC
Message-ID
<4C1A9452.1090900@pileofstuff.org>
In-Reply-To
<7v7hlyg5nh.fsf@alter.siamese.dyndns.org>

Add a notification in the command prompt specifying whether (and optionally how far) your branch has diverged from its upstream. This is especially helpful in small teams that very frequently (forget to) push to each other.

Support git-svn upstream detection as a special case, as migrators from centralised version control systems are especially likely to forget to push.

Support for other types of upstream than SVN should be easy to add if anyone is so inclined.

Signed-off-by: Andrew Sayers <andrew-git@pileofstuff.org>
---
 contrib/completion/git-completion.bash |  144 +++++++++++++++++++++++++++++++-
 1 files changed, 143 insertions(+), 1 deletions(-)
diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash
index 57245a8..6e6f458 100755
--- a/contrib/completion/git-completion.bash
+++ b/contrib/completion/git-completion.bash
@@ -42,6 +42,24 @@
 #       set GIT_PS1_SHOWUNTRACKEDFILES to a nonempty value. If there're
 #       untracked files, then a '%' will be shown next to the branch name.
 #
+#       If you would like to see the difference between HEAD and its
+#       upstream, set GIT_PS1_SHOWUPSTREAM="auto".  A "<" indicates
+#       you are behind, ">" indicates you are ahead, and "<>"
+#       indicates you have diverged.  You can further control
+#       behaviour by setting GIT_PS1_SHOWUPSTREAM to a space-separated
+#       list of values:
+#           verbose       show number of commits ahead/behind (+/-) upstream
+#           legacy        don't use the '--count' option available in recent
+#                         versions of git-rev-list
+#           git           always compare HEAD to @{upstream}
+#           svn           always compare HEAD to your SVN upstream
+#       By default, __git_ps1 will compare HEAD to your SVN upstream
+#       if it can find one, or @{upstream} otherwise.  Once you have
+#       set GIT_PS1_SHOWUPSTREAM, you can override it on a
+#       per-repository basis by setting the bash.showUpstream config
+#       variable.
+#
+#
 # To submit patches:
 #
 #    *) Read Documentation/SubmittingPatches
@@ -78,6 +96,125 @@ __gitdir ()
 	fi
 }
 
+# stores the divergence from upstream in $p
+# used by GIT_PS1_SHOWUPSTREAM
+__git_ps1_show_upstream ()
+{
+	local key value
+	local svn_remote=() svn_url_pattern count n
+	local upstream=git legacy="" verbose=""
+
+	# get some config options from git-config
+	while read key value; do
+		case "$key" in
+		bash.showupstream)
+			GIT_PS1_SHOWUPSTREAM="$value"
+			if [[ -z "${GIT_PS1_SHOWUPSTREAM}" ]]; then
+				p=""
+				return
+			fi
+			;;
+		svn-remote.*.url)
+			svn_remote[ $((${#svn_remote[@]} + 1)) ]="$value"
+			svn_url_pattern+="\\|$value"
+			upstream=svn+git # default upstream is SVN if available, else git
+			;;
+		esac
+	done < <(git config -z --get-regexp '^(svn-remote\..*\.url|bash\.showupstream)$' 2>/dev/null | tr '\0\n' '\n ')
+
+	# parse configuration values
+	for option in ${GIT_PS1_SHOWUPSTREAM}; do
+		case "$option" in
+		git|svn) upstream="$option" ;;
+		verbose) verbose=1 ;;
+		legacy)  legacy=1  ;;
+		esac
+	done
+
+	# Find our upstream
+	case "$upstream" in
+	git)    upstream="@{upstream}" ;;
+	svn*)
+		# get the upstream from the "git-svn-id: ..." in a commit message
+		# (git-svn uses essentially the same procedure internally)
+		local svn_upstream=($(git log --first-parent -1 \
+					--grep="^git-svn-id: \(${svn_url_pattern:2}\)" 2>/dev/null))
+		if [[ 0 -ne ${#svn_upstream[@]} ]]; then
+			svn_upstream=${svn_upstream[ ${#svn_upstream[@]} - 2 ]}
+			svn_upstream=${svn_upstream%@*}
+			for ((n=1; "$n" <= "${#svn_remote[@]}"; ++n)); do
+				svn_upstream=${svn_upstream#${svn_remote[$n]}}
+			done
+
+			if [[ -z "$svn_upstream" ]]; then
+				# default branch name for checkouts with no layout:
+				upstream=${GIT_SVN_ID:-git-svn}
+			else
+				upstream=${svn_upstream#/}
+			fi
+		elif [[ "svn+git" = "$upstream" ]]; then
+			upstream="@{upstream}"
+		fi
+		;;
+	esac
+
+	# Find how many commits we are ahead/behind our upstream
+	if [[ -z "$legacy" ]]; then
+		count="$(git rev-list --count --left-right \
+				"$upstream"...HEAD 2>/dev/null)"
+	else
+		# produce equivalent output to --count for older versions of git
+		local commits
+		if commits="$(git rev-list --left-right "$upstream"...HEAD 2>/dev/null)"
+		then
+			local commit behind=0 ahead=0
+			for commit in $commits
+			do
+				case "$commit" in
+				"<"*) let ++behind
+					;;
+				*)    let ++ahead
+					;;
+				esac
+			done
+			count="$behind	$ahead"
+		else
+			count=""
+		fi
+	fi
+
+	# calculate the result
+	if [[ -z "$verbose" ]]; then
+		case "$count" in
+		"") # no upstream
+			p="" ;;
+		"0	0") # equal to upstream
+			p="=" ;;
+		"0	"*) # ahead of upstream
+			p=">" ;;
+		*"	0") # behind upstream
+			p="<" ;;
+		*)	    # diverged from upstream
+			p="<>" ;;
+		esac
+	else
+		case "$count" in
+		"") # no upstream
+			p="" ;;
+		"0	0") # equal to upstream
+			p=" u=" ;;
+		"0	"*) # ahead of upstream
+			p=" u+${count#0	}" ;;
+		*"	0") # behind upstream
+			p=" u-${count%	0}" ;;
+		*)	    # diverged from upstream
+			p=" u+${count#*	}-${count%	*}" ;;
+		esac
+	fi
+
+}
+
+
 # __git_ps1 accepts 0 or 1 arguments (i.e., format string)
 # returns text to add to bash PS1 prompt (includes branch name)
 __git_ps1 ()
@@ -132,6 +269,7 @@ __git_ps1 ()
 		local s
 		local u
 		local c
+		local p
 
 		if [ "true" = "$(git rev-parse --is-inside-git-dir 2>/dev/null)" ]; then
 			if [ "true" = "$(git rev-parse --is-bare-repository 2>/dev/null)" ]; then
@@ -159,10 +297,14 @@ __git_ps1 ()
 			      u="%"
 			   fi
 			fi
+
+			if [ -n "${GIT_PS1_SHOWUPSTREAM-}" ]; then
+				__git_ps1_show_upstream
+			fi
 		fi
 
 		local f="$w$i$s$u"
-		printf "${1:- (%s)}" "$c${b##refs/heads/}${f:+ $f}$r"
+		printf "${1:- (%s)}" "$c${b##refs/heads/}${f:+ $f}$r$p"
 	fi
 }
 
-- 
1.7.0.4
Previous: Andrew SayersNext: Andrew Sayers
Message 21 of 22 in “bash completion: Support "divergence from upstream" warnings in __git_ps1”
  1. 0/2 bash completion: Support "divergence from upstream" warnings in __git_ps1Thomas Rast, Jun 12, 2010
  2. 1/2 rev-list: introduce --count optionThomas Rast, Jun 12, 2010
  3. 2/2 bash completion: Support "divergence from upstream" warnings in __git_ps1Thomas Rast, Jun 12, 2010
  4. Junio C HamanoJun 14, 2010
  5. Thomas RastJun 14, 2010
  6. SZEDER GáborJun 14, 2010
  7. vger doesn't like UTF-8 from send-emailThomas Rast, Jun 12, 2010
  8. send-email: ask about and declare 8bit mailsThomas Rast, Jun 12, 2010
  9. Junio C HamanoJun 12, 2010
  10. Thomas RastJun 13, 2010
  11. Michael WittenJun 13, 2010
  12. Erik Faye-LundJun 14, 2010
  13. bash completion: Support "divergence from upstream" messages in __git_ps1Andrew Sayers, Jun 12, 2010
  14. Thomas RastJun 14, 2010
  15. [PATCHv4] bash completion: Support "divergence from upstream" messages in __git_ps1Andrew Sayers, Jun 15, 2010
  16. Junio C HamanoJun 16, 2010
  17. Thomas RastJun 16, 2010
  18. 0/2 bash completion: Support "divergence from upstream" messages in __git_ps1Andrew Sayers, Jun 17, 2010
  19. Junio C HamanoJun 18, 2010
  20. Andrew SayersJun 18, 2010
  21. 1/2 bash completion: Support "divergence from upstream" messages in __git_ps1Andrew Sayers, Jun 17, 2010
  22. 2/2 bash-completion: Fix __git_ps1 to work with "set -u"Andrew Sayers, Jun 17, 2010

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