[PATCH] vcs_info hg: Support inactive bookmarks

[Daniel Shahaf <d.s@xxxxxxxxxxxxxxxxxx>]

After running 'hg bookmark foo -r bar', there is a difference between 'hg
checkout foo' and 'hg checkout bar'.  (The difference is similar to git
detached heads.)  vcs_info is not aware of this difference.  The attached
patch adds that feature.

Daniel

From d83abba2622936e9e5b7822bed5a399a0b5834ce Mon Sep 17 00:00:00 2001
From: Daniel Shahaf <d.s@xxxxxxxxxxxxxxxxxx>
Date: Sat, 24 Jan 2015 06:41:42 +0000
Subject: [PATCH] vcs_info hg: Support inactive bookmarks

(Similar to git detached heads)
---
 Doc/Zsh/contrib.yo                               |  7 +++++++
 Functions/VCS_Info/Backends/VCS_INFO_get_data_hg | 17 +++++++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/Doc/Zsh/contrib.yo b/Doc/Zsh/contrib.yo
index 00ede52..80a7997 100644
--- a/Doc/Zsh/contrib.yo
+++ b/Doc/Zsh/contrib.yo
@@ -927,6 +927,10 @@ kindex(get-bookmarks)
 item(tt(get-bookmarks))(
 If set to true, the tt(hg) backend will try to get a list of current
 bookmarks. They will be available via the `tt(%m)' replacement.
+
+The default is to generate a comma-separated list of all bookmark names
+that refer to the currently checked out revision.  If a bookmark is active,
+its name is suffixed an asterisk and placed first in the list.
 )
 kindex(use-prompt-escapes)
 item(tt(use-prompt-escapes))(
@@ -1290,6 +1294,9 @@ tt(get-revision) and tt(get-bookmarks) styles must be true.
 This hook gets the names of the Mercurial bookmarks that
 tt(vcs_info) collected from `hg'.
 
+If a bookmark is active, the key tt(${hook_com[hg-active-bookmark]}) is
+set to its name.  The key is otherwise unset.
+
 When setting tt(ret) to non-zero, the string in
 tt(${hook_com[hg-bookmark-string]}) will be used in the tt(%m) escape in
 tt(formats) and tt(actionformats) and will be available in the global
diff --git a/Functions/VCS_Info/Backends/VCS_INFO_get_data_hg b/Functions/VCS_Info/Backends/VCS_INFO_get_data_hg
index cedaf56..1274ca3 100644
--- a/Functions/VCS_Info/Backends/VCS_INFO_get_data_hg
+++ b/Functions/VCS_Info/Backends/VCS_INFO_get_data_hg
@@ -6,6 +6,7 @@
 setopt localoptions extendedglob NO_shwordsplit
 
 local hgbase bmfile branchfile rebasefile dirstatefile mqseriesfile \
+    curbmfile curbm \
     mqstatusfile mqguardsfile patchdir mergedir \
     r_csetid r_lrev r_branch i_bmhash i_bmname \
     revformat branchformat hgactionstring hgchanges \
@@ -24,6 +25,7 @@ r_lrev='' # local revision
 patchdir="${hgbase}/.hg/patches"
 mergedir="${hgbase}/.hg/merge/"
 bmfile="${hgbase}/.hg/bookmarks"
+curbmfile="${hgbase}/.hg/bookmarks.current"
 branchfile="${hgbase}/.hg/branch"
 rebasefile="${hgbase}/.hg/rebasestate"
 dirstatefile="${hgbase}/.hg/dirstate"
@@ -125,8 +127,23 @@ if zstyle -t ":vcs_info:${vcs}:${usercontext}:${rrn}" get-bookmarks \
         [[ $i_bmhash == $r_csetid* ]] && hgbmarks+=( $i_bmname )
     done < ${bmfile}
 
+    if [[ -r "$curbmfile" ]] ; then
+        curbm=$(<"${curbmfile}")
+        hook_com[hg-active-bookmark]=$curbm
+    else
+        # leave curbm empty and [hg-active-bookmark] undefined.
+    fi
+
     if VCS_INFO_hook 'gen-hg-bookmark-string' "${hgbmarks[@]}"; then
+        # If there is an active bookmark, annotate it and put it first.
+        if [[ -n $curbm ]] ; then
+            hgbmarks[(i)$curbm]=()
+            hgbmarks[1,0]="${curbm}*"
+        fi
         hgbmstring=${(j:, :)hgbmarks}
+        # Deannotate the array, in case later code expects it to be valid.
+        # (The order is not restored.)
+        [[ -n $curbm ]] && hgbmarks[1]=${${hgbmarks[1]}[1,-2]}
     else
         hgbmstring=${hook_com[hg-bookmark-string]}
     fi
-- 
1.9.1