Fix a bug which surfaced in commits_ahead/behind_remoteHEADmaster

If a remote branch is set, but doesn't exist (in the 'missingups'
condition), these functions would output blank ("") causing an error
when used in comparisons in color_local_commits().  It's arguable
whether the POSIX reworks caused this bug or simply revealed it, since
the previous code used bash's [[ ]] test syntax which seemed to tolerate
this case.

Restructure control flow so that any "error" in these functions yields a
result of "0".

The ahead/behind_master functions did not have this problem (the
git-rev-list command failure is already handled), but rewrite them to
match the style of the local functions.

Additionally, the git-rev-list commands are updated to use the more
straight-forward A..B syntax, dropping the use of --left-only or
--right-only.  This is more obvious code, and older git clients may
return incorrect results using the previous syntax.

Signed-off-by: Matt Hunter <m@lfurio.us>

1 files changed, 20 insertions, 26 deletions

diff --git a/git-sonar b/git-sonar
index 0cd53be..fa2237e 100755
--- a/git-sonar
+++ b/git-sonar
@@ -85,21 +85,17 @@ remote_branch_name() {
 }
 
 commits_behind_of_remote() {
-  remote_branch=${1:-"$(remote_branch_name)"}
-  if [ -n "$remote_branch" ]; then
-    git rev-list --left-only --count "${remote_branch}...HEAD" 2>/dev/null
-  else
-    printf '%s' "0"
-  fi
+  remote_branch="$1"
+  [ -n "$remote_branch" ] \
+    && git rev-list --count "HEAD..${remote_branch}" 2>/dev/null \
+    || printf '0\n'
 }
 
 commits_ahead_of_remote() {
-  remote_branch=${1:-"$(remote_branch_name)"}
-  if [ -n "$remote_branch" ]; then
-    git rev-list --right-only --count "${remote_branch}...HEAD" 2>/dev/null
-  else
-    printf '%s' "0"
-  fi
+  remote_branch="$1"
+  [ -n "$remote_branch" ] \
+    && git rev-list --count "${remote_branch}..HEAD" 2>/dev/null \
+    || printf '0\n'
 }
 
 determine_tracked_remote() {
@@ -113,23 +109,21 @@ determine_tracked_remote() {
 }
 
 remote_behind_of_master() {
-  remote_branch=${1:-"$(remote_branch_name)"}
-  tracked_remote=$(determine_tracked_remote)
-  if [ -n "$remote_branch" ] && [ "$remote_branch" != "$tracked_remote" ]; then
-    git rev-list --left-only --count "${tracked_remote}...${remote_branch}" 2>/dev/null || printf '%s' "0"
-  else
-    printf '%s' "0"
-  fi
+  remote_branch="$1"
+  tracked_remote="$(determine_tracked_remote)"
+  [ -n "$remote_branch" ] \
+    && [ "$remote_branch" != "$tracked_remote" ] \
+    && git rev-list --count "${remote_branch}..${tracked_remote}" 2>/dev/null \
+    || printf '0\n'
 }
 
 remote_ahead_of_master() {
-  remote_branch=${1:-"$(remote_branch_name)"}
-  tracked_remote=$(determine_tracked_remote)
-  if [ -n "$remote_branch" ] && [ "$remote_branch" != "$tracked_remote" ]; then
-    git rev-list --right-only --count "${tracked_remote}...${remote_branch}" 2>/dev/null || printf '%s' "0"
-  else
-    printf '%s' "0"
-  fi
+  remote_branch="$1"
+  tracked_remote="$(determine_tracked_remote)"
+  [ -n "$remote_branch" ] \
+    && [ "$remote_branch" != "$tracked_remote" ] \
+    && git rev-list --count "${tracked_remote}..${remote_branch}" 2>/dev/null \
+    || printf '0\n'
 }
 
 # Diacritic marks for overlaying an arrow over A D C etc