git-prompt: add quiet upstream indicator option

index 637a6f13a6..7628bc10fe 100755
@@ -18,26 +18,21 @@ c_green='\001\e[32m\002'
 c_lblue='\001\e[1;34m\002'
 c_clear='\001\e[0m\002'
 
+# (main)                     (b1)
+# initial (t1) - second-b1 - third-b1 (t2)
+#             \
+#              second-b2 - another-b2 - yet-another-b2
+#                                       (b2)
 test_expect_success 'setup for prompt tests' '
 	git init otherrepo &&
-	echo 1 >file &&
-	git add file &&
-	test_tick &&
-	git commit -m initial &&
-	git tag -a -m msg1 t1 &&
+	test_commit --annotate initial file contents1 t1 &&
 	git checkout -b b1 &&
-	echo 2 >file &&
-	git commit -m "second b1" file &&
-	echo 3 >file &&
-	git commit -m "third b1" file &&
-	git tag -a -m msg2 t2 &&
+	test_commit --no-tag second-b1 file &&
+	test_commit --annotate third-b1 file contents2 t2 &&
 	git checkout -b b2 main &&
-	echo 0 >file &&
-	git commit -m "second b2" file &&
-	echo 00 >file &&
-	git commit -m "another b2" file &&
-	echo 000 >file &&
-	git commit -m "yet another b2" file &&
+	test_commit --no-tag second-b2 file &&
+	test_commit --no-tag another-b2 file &&
+	test_commit --no-tag yet-another-b2 file &&
 	mkdir ignored_dir &&
 	echo "ignored_dir/" >>.gitignore &&
 	git checkout main

index 7628bc10fe..3997012d1c 100755
@@ -25,6 +25,8 @@ c_clear='\001\e[0m\002'
 #                                       (b2)
 test_expect_success 'setup for prompt tests' '
 	git init otherrepo &&
+	git init --bare origin.git &&
+	git remote add origin origin.git &&
 	test_commit --annotate initial file contents1 t1 &&
 	git checkout -b b1 &&
 	test_commit --no-tag second-b1 file &&

@@ -35,6 +37,7 @@ test_expect_success 'setup for prompt tests' '
 	test_commit --no-tag yet-another-b2 file &&
 	mkdir ignored_dir &&
 	echo "ignored_dir/" >>.gitignore &&
+	git push --set-upstream origin main b1 b2 &&
 	git checkout main
 '
 

@@ -515,6 +518,62 @@ test_expect_success 'prompt - untracked files status indicator - not shown insid
 	test_cmp expected "$actual"
 '
 
+################################################################
+# Show Upstream
+options=(          short  verbose   'verbose name'    )
+expected_equal=(   ' ='   '|u='     '|u= origin/main' )
+expected_ahead=(   ' >'   '|u+1'    '|u+1 origin/main')
+expected_behind=(  ' <'   '|u-1'    '|u-1 origin/b1'  )
+expected_diverged=(' <>'  '|u+1-1'  '|u+1-1 origin/b1')
+
+for i in ${!options[@]}
+do
+	option=${options[$i]}
+
+	test_expect_success "prompt - upstream status indicator - $option - equal" '
+		printf " (main${expected_equal[$i]})" >expected &&
+		GIT_PS1_SHOWUPSTREAM=$option &&
+		test_when_finished "sane_unset GIT_PS1_SHOWUPSTREAM" &&
+		__git_ps1 >"$actual" &&
+		test_cmp expected "$actual"
+	'
+
+	test_expect_success "prompt - upstream status indicator - $option - ahead" '
+		printf " (main${expected_ahead[$i]})" >expected &&
+		GIT_PS1_SHOWUPSTREAM=$option &&
+		test_when_finished "sane_unset GIT_PS1_SHOWUPSTREAM" &&
+		test_commit --no-tag ahead &&
+		test_when_finished "git reset HEAD^" &&
+		__git_ps1 >"$actual" &&
+		test_cmp expected "$actual"
+	'
+
+	test_expect_success "prompt - upstream status indicator - $option - behind" '
+		printf " (b1${expected_behind[$i]})" >expected &&
+		GIT_PS1_SHOWUPSTREAM=$option &&
+		test_when_finished "sane_unset GIT_PS1_SHOWUPSTREAM" &&
+		git checkout b1 &&
+		test_when_finished "git checkout main" &&
+		git reset HEAD^ &&
+		test_when_finished "git reset @{u}" &&
+		__git_ps1 >"$actual" &&
+		test_cmp expected "$actual"
+	'
+
+	test_expect_success "prompt - upstream status indicator - $option - diverged" '
+		printf " (b1${expected_diverged[$i]})" >expected &&
+		GIT_PS1_SHOWUPSTREAM=$option &&
+		test_when_finished "sane_unset GIT_PS1_SHOWUPSTREAM" &&
+		git checkout b1 &&
+		test_when_finished "git checkout main" &&
+		git reset HEAD^ &&
+		test_when_finished "git reset @{u}" &&
+		test_commit --no-tag ahead &&
+		__git_ps1 >"$actual" &&
+		test_cmp expected "$actual"
+	'
+done
+
 test_expect_success 'prompt - format string starting with dash' '
 	printf -- "-main" >expected &&
 	__git_ps1 "-%s" >"$actual" &&

index 6186c474ba..be23c522da 100644
@@ -55,13 +55,14 @@
 # enabled.
 #
 # 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, "<>" indicates you have diverged and "="
-# indicates that there is no difference. You can further control
+# set GIT_PS1_SHOWUPSTREAM to a nonempty value.  A "<" indicates you are
+# behind, ">" indicates you are ahead, "<>" indicates you have diverged
+# and "=" indicates that there is no difference.  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
+#     quiet         omit '=' when there is no difference to the upstream
 #     name          if verbose, then also show the upstream abbrev name
 #     legacy        don't use the '--count' option available in recent
 #                   versions of git-rev-list

@@ -157,7 +158,7 @@ __git_ps1_show_upstream ()
 {
 	local key value
 	local svn_remotes="" svn_url_pattern="" count n
-	local upstream_type=git legacy="" verbose="" name=""
+	local upstream_type=git legacy="" verbose="" quiet="" name=""
 	local LF="$__git_LF"
 
 	# get some config options from git-config

@@ -187,6 +188,7 @@ __git_ps1_show_upstream ()
 		case "$option" in
 		git|svn) upstream_type="$option" ;;
 		verbose) verbose=1 ;;
+		quiet)   quiet=1   ;;
 		legacy)  legacy=1  ;;
 		name)    name=1 ;;
 		esac

@@ -262,6 +264,8 @@ __git_ps1_show_upstream ()
 		"") # no upstream
 			p="" ;;
 		"0	0") # equal to upstream
+			[ "$quiet" ] &&
+			p="" ||
 			p="=" ;;
 		"0	"*) # ahead of upstream
 			p=">" ;;

@@ -275,6 +279,8 @@ __git_ps1_show_upstream ()
 		"") # no upstream
 			upstream="" ;;
 		"0	0") # equal to upstream
+			[ "$quiet" ] &&
+			upstream="|u" ||
 			upstream="|u=" ;;
 		"0	"*) # ahead of upstream
 			upstream="|u+${count#0	}" ;;

index 3997012d1c..855428f007 100755
@@ -520,11 +520,11 @@ test_expect_success 'prompt - untracked files status indicator - not shown insid
 
 ################################################################
 # Show Upstream
-options=(          short  verbose   'verbose name'    )
-expected_equal=(   ' ='   '|u='     '|u= origin/main' )
-expected_ahead=(   ' >'   '|u+1'    '|u+1 origin/main')
-expected_behind=(  ' <'   '|u-1'    '|u-1 origin/b1'  )
-expected_diverged=(' <>'  '|u+1-1'  '|u+1-1 origin/b1')
+options=(          short  verbose   'verbose name'      quiet   'verbose quiet'  'verbose name quiet')
+expected_equal=(   ' ='   '|u='     '|u= origin/main'   ''      '|u'             '|u origin/main'    )
+expected_ahead=(   ' >'   '|u+1'    '|u+1 origin/main'  ' >'    '|u+1'           '|u+1 origin/main'  )
+expected_behind=(  ' <'   '|u-1'    '|u-1 origin/b1'    ' <'    '|u-1'           '|u-1 origin/b1'    )
+expected_diverged=(' <>'  '|u+1-1'  '|u+1-1 origin/b1'  ' <>'   '|u+1-1'         '|u+1-1 origin/b1'  )
 
 for i in ${!options[@]}
 do