completion: Better __git_ps1 support when not in working directory

If .git/HEAD is not readable, __git_ps1 does nothing.

If --is-in-git-dir, __git_ps1 returns " (GIT_DIR!)" as a cautionary
note. The previous behavior would show the branch name (and would
optionally attempt to determine the dirtyState of the directory, which
was impossible because a "git diff" was used).

If --is-in-work-tree, __git_ps1 returns the branch name. Additionally,
if showDirtyState is on, the dirty state is displayed.

Signed-off-by: Ted Pavlic <ted@tedpavlic.com>
Acked-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash
index c61576fcafc7b3911f10995a62940c11149d83e8..aa8eec24d9847b82ced35d47f3a58bfe8203ac82 100755 (executable)
--- a/contrib/completion/git-completion.bash
+++ b/contrib/completion/git-completion.bash
@@ -108,7 +108,9 @@ __git_ps1 ()
                        fi
                        if ! b="$(git symbolic-ref HEAD 2>/dev/null)"; then
                                if ! b="$(git describe --exact-match HEAD 2>/dev/null)"; then
-                                       b="$(cut -c1-7 "$g/HEAD")..."
+                                       if [ -r "$g/HEAD" ]; then
+                                               b="$(cut -c1-7 "$g/HEAD")..."
+                                       fi
                                fi
                        fi
                fi
@@ -116,23 +118,29 @@ __git_ps1 ()
                local w
                local i
 
-               if [ -n "${GIT_PS1_SHOWDIRTYSTATE-}" ]; then
-                       if [ "$(git config --bool bash.showDirtyState)" != "false" ]; then
-                               git diff --no-ext-diff --ignore-submodules \
-                                       --quiet --exit-code || w="*"
-                               if git rev-parse --quiet --verify HEAD >/dev/null; then
-                                       git diff-index --cached --quiet \
-                                               --ignore-submodules HEAD -- || i="+"
-                               else
-                                       i="#"
+               if [ "true" = "$(git rev-parse --is-inside-git-dir 2>/dev/null)" ]; then
+                       b="GIT_DIR!"
+               elif [ "true" = "$(git rev-parse --is-inside-work-tree 2>/dev/null)" ]; then
+                       if [ -n "${GIT_PS1_SHOWDIRTYSTATE-}" ]; then
+                               if [ "$(git config --bool bash.showDirtyState)" != "false" ]; then
+                                       git diff --no-ext-diff --ignore-submodules \
+                                               --quiet --exit-code || w="*"
+                                       if git rev-parse --quiet --verify HEAD >/dev/null; then
+                                               git diff-index --cached --quiet \
+                                                       --ignore-submodules HEAD -- || i="+"
+                                       else
+                                               i="#"
+                                       fi
                                fi
                        fi
                fi
 
-               if [ -n "${1-}" ]; then
-                       printf "$1" "${b##refs/heads/}$w$i$r"
-               else
-                       printf " (%s)" "${b##refs/heads/}$w$i$r"
+               if [ -n "$b" ]; then
+                       if [ -n "${1-}" ]; then
+                               printf "$1" "${b##refs/heads/}$w$i$r"
+                       else
+                               printf " (%s)" "${b##refs/heads/}$w$i$r"
+                       fi
                fi
        fi
 }