Default to updating all git branches on fetch (#571)

Co-authored-by: Sindre Sorhus <sindresorhus@gmail.com>

pure.zsh

@@ -300,19 +300,23 @@ prompt_pure_async_git_dirty() {
 prompt_pure_async_git_fetch() {
 	setopt localoptions noshwordsplit
 
+	local only_upstream=${1:-0}
+
 	# Sets `GIT_TERMINAL_PROMPT=0` to disable authentication prompt for Git fetch (Git 2.3+).
 	export GIT_TERMINAL_PROMPT=0
 	# Set SSH `BachMode` to disable all interactive SSH password prompting.
 	export GIT_SSH_COMMAND="${GIT_SSH_COMMAND:-"ssh"} -o BatchMode=yes"
 
-	local ref
-	ref=$(command git symbolic-ref -q HEAD)
 	local -a remote
-	remote=($(command git for-each-ref --format='%(upstream:remotename) %(refname)' $ref))
-
-	if [[ -z $remote[1] ]]; then
-		# No remote specified for this branch, skip fetch.
-		return 97
+	if ((only_upstream)); then
+		local ref
+		ref=$(command git symbolic-ref -q HEAD)
+		# Set remote to only fetch information for the current branch.
+		remote=($(command git for-each-ref --format='%(upstream:remotename) %(refname)' $ref))
+		if [[ -z $remote[1] ]]; then
+			# No remote specified for this branch, skip fetch.
+			return 97
+		fi
 	fi
 
 	# Default return code, which indicates Git fetch failure.
@@ -340,8 +344,8 @@ prompt_pure_async_git_fetch() {
 		fi
 	' CHLD
 
-	# Only fetch information for the current branch and avoid
-	# fetching tags or submodules to speed up the process.
+	# Do git fetch and avoid fetching tags or
+	# submodules to speed up the process.
 	command git -c gc.auto=0 fetch \
 		--quiet \
 		--no-tags \
@@ -438,8 +442,9 @@ prompt_pure_async_refresh() {
 
 	# Do not perform `git fetch` if it is disabled or in home folder.
 	if (( ${PURE_GIT_PULL:-1} )) && [[ $prompt_pure_vcs_info[top] != $HOME ]]; then
-		# Tell the async worker to do a `git fetch`.
-		async_job "prompt_pure" prompt_pure_async_git_fetch
+		zstyle -t :prompt:pure:git:fetch only_upstream
+		local only_upstream=$((? == 0))
+		async_job "prompt_pure" prompt_pure_async_git_fetch $only_upstream
 	fi
 
 	# If dirty checking is sufficiently fast,

readme.md

@@ -96,10 +96,16 @@ prompt pure
 | **`PURE_GIT_UP_ARROW`**          | Defines the git up arrow symbol.                                                               | `⇡`            |
 | **`PURE_GIT_STASH_SYMBOL`**      | Defines the git stash symbol.                                                                  | `≡`            |
 
+## Zstyle options
+
 Showing git stash status as part of the prompt is not activated by default. To activate this you'll need to opt in via `zstyle`:
 
 `zstyle :prompt:pure:git:stash show yes`
 
+You can set Pure to only `git fetch` the upstream branch of the current local branch. In some cases, this can result in faster updates for Git arrows, but for most users, it's better to leave this setting disabled. You can enable it with:
+
+`zstyle :prompt:pure:git:fetch only_upstream yes`
+
 ## Colors
 
 As explained in ZSH's [manual](http://zsh.sourceforge.net/Doc/Release/Zsh-Line-Editor.html#Character-Highlighting), color values can be: