[PATCH va/i18n-even-more] rebase-interactive: trim leading whitespace from progress count

Interactive rebase uses 'wc -l' to write the current patch number
in a progress report. Some implementations of 'wc -l' produce spaces
before the number, leading to ugly output such as

  Rebasing (     3/8)

Remove the spaces using a trivial arithmetic evaluation.

Before 9588c52 (i18n: rebase-interactive: mark strings for
translation) this was not a problem because printf was used to
generate the text. Since that commit, the count is interpolated
directly from a shell variable into the text, where the spaces
remain. The total number of patches does not have this problem
even though it is interpolated from a shell variable in the same
manner, because the variable is set by an arithmetic evaluation.

Later in the script, there is a virtually identical case where
leading spaces are trimmed, but it uses a pattern substitution:

todocount=$(git stripspace --strip-comments <"$todo" | wc -l)
todocount=${todocount##* }

I did not choose this idiom because it adds a line of code, and
there is already an arithmetic evaluation in the vicinity of the
line that is changed here.

Signed-off-by: Johannes Sixt <redacted>
---
 git-rebase--interactive.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index ded4595..e2da524 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh

@@ -121,7 +121,7 @@ mark_action_done () {
 	sed -e 1q < "$todo" >> "$done"
 	sed -e 1d < "$todo" >> "$todo".new
 	mv -f "$todo".new "$todo"
-	new_count=$(git stripspace --strip-comments <"$done" | wc -l)
+	new_count=$(( $(git stripspace --strip-comments <"$done" | wc -l) ))
 	echo $new_count >"$msgnum"
 	total=$(($new_count + $(git stripspace --strip-comments <"$todo" | wc -l)))
 	echo $total >"$end"

-- 
2.9.0.443.ga8520ad

On Thu, Jul 28, 2016 at 1:47 PM, Johannes Sixt [off-list ref] wrote:

Interactive rebase uses 'wc -l' to write the current patch number
in a progress report. Some implementations of 'wc -l' produce spaces
before the number, leading to ugly output such as

  Rebasing (     3/8)

Remove the spaces using a trivial arithmetic evaluation.

Before 9588c52 (i18n: rebase-interactive: mark strings for
translation) this was not a problem because printf was used to
generate the text. Since that commit, the count is interpolated
directly from a shell variable into the text, where the spaces
remain. The total number of patches does not have this problem
even though it is interpolated from a shell variable in the same
manner, because the variable is set by an arithmetic evaluation.

Later in the script, there is a virtually identical case where
leading spaces are trimmed, but it uses a pattern substitution:

todocount=$(git stripspace --strip-comments <"$todo" | wc -l)
todocount=${todocount##* }

I did not choose this idiom because it adds a line of code, and
there is already an arithmetic evaluation in the vicinity of the
line that is changed here.

On the other hand, to a newcomer (not familiar with this patch),
${foo##* } is an obvious and intentional stripping of whitespace,
whereas taking advantage of a side-effect of arithmetic evaluation to
achieve the same is quite subtle and likely to be interpreted as
pointless, thus forces the reader to consult 'blame' to understand why
the code is the way it is.

W dniu 2016-07-28 o 20:22, Eric Sunshine pisze:

On Thu, Jul 28, 2016 at 1:47 PM, Johannes Sixt [off-list ref] wrote:

quoted

Interactive rebase uses 'wc -l' to write the current patch number
in a progress report. Some implementations of 'wc -l' produce spaces
before the number, leading to ugly output such as

  Rebasing (     3/8)

Remove the spaces using a trivial arithmetic evaluation.

Before 9588c52 (i18n: rebase-interactive: mark strings for
translation) this was not a problem because printf was used to
generate the text. Since that commit, the count is interpolated
directly from a shell variable into the text, where the spaces
remain. The total number of patches does not have this problem
even though it is interpolated from a shell variable in the same
manner, because the variable is set by an arithmetic evaluation.

Later in the script, there is a virtually identical case where
leading spaces are trimmed, but it uses a pattern substitution:

todocount=$(git stripspace --strip-comments <"$todo" | wc -l)
todocount=${todocount##* }

I did not choose this idiom because it adds a line of code, and
there is already an arithmetic evaluation in the vicinity of the
line that is changed here.

On the other hand, to a newcomer (not familiar with this patch),
${foo##* } is an obvious and intentional stripping of whitespace,
whereas taking advantage of a side-effect of arithmetic evaluation to
achieve the same is quite subtle and likely to be interpreted as
pointless, thus forces the reader to consult 'blame' to understand why
the code is the way it is.

On the gripping hand, the number of currently processed commits
(instructions) in an interactive rebase is a number, and arithmetic
expansion can be understood as shell equivalent of casting to integer.

quoted

Signed-off-by: Johannes Sixt <redacted>
---

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh

@@ -121,7 +121,7 @@ mark_action_done () {
        sed -e 1q < "$todo" >> "$done"
        sed -e 1d < "$todo" >> "$todo".new
        mv -f "$todo".new "$todo"
-       new_count=$(git stripspace --strip-comments <"$done" | wc -l)
+       new_count=$(( $(git stripspace --strip-comments <"$done" | wc -l) ))
        echo $new_count >"$msgnum"
        total=$(($new_count + $(git stripspace --strip-comments <"$todo" | wc -l)))
        echo $total >"$end"