[PATCH] completion: fix issue with process substitution not working on Git for Windows

Git for Windows comes with a bash that doesn't support process substitution.
It issues the following error when using git-completion.bash with
GIT_PS1_SHOWUPSTREAM set:

$ export GIT_PS1_SHOWUPSTREAM=1
sh.exe": cannot make pipe for process substitution: Function not implemented
sh.exe": cannot make pipe for process substitution: Function not implemented
sh.exe": <(git config -z --get-regexp '^(svn-remote\..*\.url|bash\.showupstream)$' 2>/dev/null | tr '\0\n' '\n '): ambiguous redirect

Replace the process substitution with a simple "echo $var | while...".

Signed-off-by: Stefan Naewe <redacted>
---
 contrib/completion/git-completion.bash |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash
index 8648a36..926db80 100755
--- a/contrib/completion/git-completion.bash
+++ b/contrib/completion/git-completion.bash

@@ -110,6 +110,8 @@ __git_ps1_show_upstream ()
 	local upstream=git legacy="" verbose=""
 
 	# get some config options from git-config
+	output="$(git config -z --get-regexp '^(svn-remote\..*\.url|bash\.showupstream)$' 2>/dev/null | tr '\0\n' '\n ')"
+	echo "$output" | \
 	while read key value; do
 		case "$key" in
 		bash.showupstream)

@@ -125,7 +127,7 @@ __git_ps1_show_upstream ()
 			upstream=svn+git # default upstream is SVN if available, else git
 			;;
 		esac
-	done < <(git config -z --get-regexp '^(svn-remote\..*\.url|bash\.showupstream)$' 2>/dev/null | tr '\0\n' '\n ')
+	done
 
 	# parse configuration values
 	for option in ${GIT_PS1_SHOWUPSTREAM}; do

-- 
1.7.7.1

Am 25.10.2011 20:01, schrieb Stefan Naewe:

Are you sure that the result still works as intended? The while loop
sets a few variables. When you place it in a pipe, the loop runs in a
subshell, and subsequent code will not see the modified values. Unless
bash knows how to optimize away the subshell, that is.

OTOH, when you use while ...; do ...; done < <(...), the while loop is
not in a subshell.

An alternative is to use:  while ...; do ...; done <<< "$output"

BTW, you don't need to protect the end-of-line with a backslash if the
line ends with the pipe symbol.

-- Hannes

Am 25. Oktober 2011 22:39 schrieb Johannes Sixt [off-list ref]:

Am 25.10.2011 20:01, schrieb Stefan Naewe:

quoted

Git for Windows comes with a bash that doesn't support process substitution.
It issues the following error when using git-completion.bash with
GIT_PS1_SHOWUPSTREAM set:

$ export GIT_PS1_SHOWUPSTREAM=1
sh.exe": cannot make pipe for process substitution: Function not implemented
sh.exe": cannot make pipe for process substitution: Function not implemented
sh.exe": <(git config -z --get-regexp '^(svn-remote\..*\.url|bash\.showupstream)$' 2>/dev/null | tr '\0\n' '\n '): ambiguous redirect

Replace the process substitution with a simple "echo $var | while...".

Signed-off-by: Stefan Naewe <redacted>
---
 contrib/completion/git-completion.bash |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash
index 8648a36..926db80 100755
--- a/contrib/completion/git-completion.bash
+++ b/contrib/completion/git-completion.bash

@@ -110,6 +110,8 @@ __git_ps1_show_upstream ()

      local upstream=git legacy="" verbose=""

      # get some config options from git-config
+     output="$(git config -z --get-regexp '^(svn-remote\..*\.url|bash\.showupstream)$' 2>/dev/null | tr '\0\n' '\n ')"
+     echo "$output" | \
      while read key value; do
              case "$key" in
              bash.showupstream)

@@ -125,7 +127,7 @@ __git_ps1_show_upstream ()

                      upstream=svn+git # default upstream is SVN if available, else git
                      ;;
              esac
-     done < <(git config -z --get-regexp '^(svn-remote\..*\.url|bash\.showupstream)$' 2>/dev/null | tr '\0\n' '\n ')
+     done

      # parse configuration values
      for option in ${GIT_PS1_SHOWUPSTREAM}; do

Are you sure that the result still works as intended? The while loop
sets a few variables. When you place it in a pipe, the loop runs in a
subshell, and subsequent code will not see the modified values. Unless
bash knows how to optimize away the subshell, that is.

I doesn't work in the 'git svn' case, I guess.

OTOH, when you use while ...; do ...; done < <(...), the while loop is
not in a subshell.

An alternative is to use:  while ...; do ...; done <<< "$output"

I'll try that.

BTW, you don't need to protect the end-of-line with a backslash if the
line ends with the pipe symbol.

OK. Will do.

-- Hannes

Thanks,
  Stefan
-- 
----------------------------------------------------------------
python -c "print '73746566616e2e6e6165776540676d61696c2e636f6d'.decode('hex')"

Git for Windows comes with a bash that doesn't support process substitution.
It issues the following error when using git-completion.bash with
GIT_PS1_SHOWUPSTREAM set:

$ export GIT_PS1_SHOWUPSTREAM=1
sh.exe": cannot make pipe for process substitution: Function not implemented
sh.exe": cannot make pipe for process substitution: Function not implemented
sh.exe": <(git config -z --get-regexp '^(svn-remote\..*\.url|bash\.showupstream)$' 2>/dev/null | tr '\0\n' '\n '): ambiguous redirect

Replace the process substitution with a 'here string'.

Signed-off-by: Stefan Naewe <redacted>
---
 contrib/completion/git-completion.bash |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash
index 8648a36..0b3d47e 100755
--- a/contrib/completion/git-completion.bash
+++ b/contrib/completion/git-completion.bash

@@ -110,6 +110,7 @@ __git_ps1_show_upstream ()
 	local upstream=git legacy="" verbose=""
 
 	# get some config options from git-config
+	output="$(git config -z --get-regexp '^(svn-remote\..*\.url|bash\.showupstream)$' 2>/dev/null | tr '\0\n' '\n ')"
 	while read key value; do
 		case "$key" in
 		bash.showupstream)

@@ -125,7 +126,7 @@ __git_ps1_show_upstream ()
 			upstream=svn+git # default upstream is SVN if available, else git
 			;;
 		esac
-	done < <(git config -z --get-regexp '^(svn-remote\..*\.url|bash\.showupstream)$' 2>/dev/null | tr '\0\n' '\n ')
+	done <<< "$output"
 
 	# parse configuration values
 	for option in ${GIT_PS1_SHOWUPSTREAM}; do

-- 
1.7.7.1

Stefan Naewe [off-list ref] writes:

Git for Windows comes with a bash that doesn't support process substitution.
It issues the following error when using git-completion.bash with
GIT_PS1_SHOWUPSTREAM set:

$ export GIT_PS1_SHOWUPSTREAM=1
sh.exe": cannot make pipe for process substitution: Function not implemented
sh.exe": cannot make pipe for process substitution: Function not implemented
sh.exe": <(git config -z --get-regexp '^(svn-remote\..*\.url|bash\.showupstream)$' 2>/dev/null | tr '\0\n' '\n '): ambiguous redirect

Replace the process substitution with a 'here string'.

Signed-off-by: Stefan Naewe <redacted>

Yuck, but I honestly shouldn't care about the yuckiness as this script is
inherently intimately dependent on bash anyway ;-).

On Wed, Oct 26, 2011 at 09:13:09PM +0200, Stefan Naewe wrote:

The $output variable is not declared as local and therefore it leaks
into the environment.  But instead of declaring it local, why not
eliminate it altogether, and use the "$(git config ....)" command
substitution as here string?


Gábor

On Thu, 27 Oct 2011 11:05:30 +0200
SZEDER Gábor [off-list ref] wrote:

On Wed, Oct 26, 2011 at 09:13:09PM +0200, Stefan Naewe wrote:

quoted

Git for Windows comes with a bash that doesn't support process substitution.
It issues the following error when using git-completion.bash with
GIT_PS1_SHOWUPSTREAM set:

$ export GIT_PS1_SHOWUPSTREAM=1
sh.exe": cannot make pipe for process substitution: Function not implemented
sh.exe": cannot make pipe for process substitution: Function not implemented
sh.exe": <(git config -z --get-regexp '^(svn-remote\..*\.url|bash\.showupstream)$' 2>/dev/null | tr '\0\n' '\n '): ambiguous redirect

Replace the process substitution with a 'here string'.

Signed-off-by: Stefan Naewe <redacted>
---
 contrib/completion/git-completion.bash |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash
index 8648a36..0b3d47e 100755
--- a/contrib/completion/git-completion.bash
+++ b/contrib/completion/git-completion.bash

@@ -110,6 +110,7 @@ __git_ps1_show_upstream ()
 	local upstream=git legacy="" verbose=""
 
 	# get some config options from git-config
+	output="$(git config -z --get-regexp '^(svn-remote\..*\.url|bash\.showupstream)$' 2>/dev/null | tr '\0\n' '\n ')"
 	while read key value; do
 		case "$key" in
 		bash.showupstream)

@@ -125,7 +126,7 @@ __git_ps1_show_upstream ()
 			upstream=svn+git # default upstream is SVN if available, else git
 			;;
 		esac
-	done < <(git config -z --get-regexp '^(svn-remote\..*\.url|bash\.showupstream)$' 2>/dev/null | tr '\0\n' '\n ')
+	done <<< "$output"

The $output variable is not declared as local and therefore it leaks
into the environment.  But instead of declaring it local, why not
eliminate it altogether, and use the "$(git config ....)" command
substitution as here string?

Wouldn't this work:

	git config -z --get-regexp '^(svn-remote\..*\.url|bash\.showupstream)$' 2>/dev/null | tr '\0\n' '\n ' | \
	while read key value; do
		...
	done

- xkr47

On Thu, 27 Oct 2011 13:27:54 +0300
Jonas Berlin [off-list ref] wrote:

On Thu, 27 Oct 2011 11:05:30 +0200
SZEDER Gábor [off-list ref] wrote:

quoted

The $output variable is not declared as local and therefore it leaks
into the environment.  But instead of declaring it local, why not
eliminate it altogether, and use the "$(git config ....)" command
substitution as here string?

Wouldn't this work:

	git config -z --get-regexp '^(svn-remote\..*\.url|bash\.showupstream)$' 2>/dev/null | tr '\0\n' '\n ' | \
	while read key value; do
		...
	done

Sorry, please disregard, I didn't notice it was already dismissed in v1 of the PATCH..

- xkr47