[OE-core] [PATCH 1/1] oe-init-build-env, scripts/oe-buildenv-internal: add error detecting for $BDIR

[Cui, Dexuan]

Darren Hart wrote on 2011-08-04:
> On 08/04/2011 12:37 AM, Cui, Dexuan wrote:
> Please remember to include a description of the problem and the
> approach taken to fix it. This eliminates wasted time trying to
> decipher it later or by people unfamiliar with the history. This is important even for simple changes.
> In this case something like:
> 
> " The previous fix for a bug in Ubuntu 10.04 readlink, $COMMIT_ID,
> notified the user when a trailing slash was used. As there is no
> semantic difference, simply remove any trailing slashes and proceed
> without nagging the user. "
Thanks! I'll use the description.

>> diff --git a/scripts/oe-buildenv-internal
>> b/scripts/oe-buildenv-internal index 117b0c5..4a44174 100755
>> --- a/scripts/oe-buildenv-internal
>> +++ b/scripts/oe-buildenv-internal
>> @@ -28,14 +28,16 @@ if [ "x$BDIR" = "x" ]; then
>>      if [ "x$1" = "x" ]; then
>>          BDIR="build"
>>      else
>> -        BDIR=`readlink -f "$1"` -        if [ -z "$BDIR"  ]; then -   
>>         if expr "$1" : '.*/$' >/dev/null; then -                echo
>> >&2 "Error: please remove any trailing / in the argument." -           
>> else -                PARENTDIR=`dirname "$1"` -                echo
>> >&2 "Error: the directory $PARENTDIR doesn't exist?" -            fi + 
>>       BDIR="$1" +        if [ "$BDIR" = "/" ]; then +            echo
>> >&2 "Error: / is not supported as a build directory." +           
>> return 1 +        fi +        BDIR=`echo $BDIR | sed -re 's|/+$||'` +  
>>      BDIR=`readlink -f "$BDIR"` +        if [ -z "$BDIR" ]; then +     
>>       PARENTDIR=`dirname "$1"` +            echo >&2 "Error: the
>> directory $PARENTDIR doesn't exist?"
> 
> This shouldn't be a question. If the documented behavior of readlink
> is to return empty when the path doesn't exist, then assume this to be the case.
The latest manual of readlink says readlink should ignore trailing slash.

> Also, it is a good idea to avoid contractions in printed error messages.
> 
> 	echo >&2 "Error: the directory $PARENTDIR does not exist."
Ok, I'll change "doesn't" to "does not".

> Otherwise, this looks good to me.
Please review the new patch (I paste it at the end of the mail, too)
http://git.yoctoproject.org/cgit/cgit.cgi/poky-contrib/commit/?h=dcui/bug-671&id=593e3506f4d4d9f6030100eac8c8e0af7f8ce3eb

Thanks!
-- Dexuan

commit 593e3506f4d4d9f6030100eac8c8e0af7f8ce3eb
Author: Dexuan Cui <dexuan.cui at intel.com>
Date:   Thu Aug 4 14:53:20 2011 +0800

    scripts/oe-buildenv-internal: improve the error detecting for $BDIR

    Thanks a lot to Darren Hart and Paul Eggleton's suggestions!

    A description of this improvement from Darren is:
    "
    The previous fix for a bug in Ubuntu 10.04 readlink,
    be2a2764d8ceb398d81714661e6f199c8b11946c, notified the user when a trailing
    slash was used. As there is no semantic difference, simply remove any
    trailing slashes and proceed without nagging the user.
    "

    Signed-off-by: Dexuan Cui <dexuan.cui at intel.com>

diff --git a/scripts/oe-buildenv-internal b/scripts/oe-buildenv-internal
index 117b0c5..9988c9f 100755
--- a/scripts/oe-buildenv-internal
+++ b/scripts/oe-buildenv-internal
@@ -28,14 +28,22 @@ if [ "x$BDIR" = "x" ]; then
     if [ "x$1" = "x" ]; then
         BDIR="build"
     else
-        BDIR=`readlink -f "$1"`
-        if [ -z "$BDIR"  ]; then
-            if expr "$1" : '.*/$' >/dev/null; then
-                echo >&2 "Error: please remove any trailing / in the argument."
-            else
-                PARENTDIR=`dirname "$1"`
-                echo >&2 "Error: the directory $PARENTDIR doesn't exist?"
-            fi
+        BDIR="$1"
+        if [ "$BDIR" = "/" ]; then
+            echo >&2 "Error: / is not supported as a build directory."
+            return 1
+        fi
+
+        # Remove possible trailing slash. This is used to work around
+        # buggy readlink of Ubuntu 10.04 that doesn't ignore trailing slash
+        # and hence "readlink -f new_dir_to_be_created/" returns empty.
+        # See YOCTO #671 for details.
+        BDIR=`echo $BDIR | sed -re 's|/+$||'`
+
+        BDIR=`readlink -f "$BDIR"`
+        if [ -z "$BDIR" ]; then
+            PARENTDIR=`dirname "$1"`
+            echo >&2 "Error: the directory $PARENTDIR does not exist?"
             return 1
         fi
     fi