[#306] [#457] [#458] Fix regression in ydbinstall.sh that caused it t…

…o fail with YDB-E-SYSCALL errors

* `ydbinstall.sh` was observed to fail with the below error when one tried to install YDB as well as at
  least one plugin (posix, zlib, encryption plugin).

  ```
  + echo Error file at /tmp/ydb_env_20174_GQOTSJ is:
  Error file at /tmp/ydb_env_20174_GQOTSJ is:
  + cat /tmp/ydb_env_20174_GQOTSJ/err
  %YDB-E-SYSCALL, Error received from system call getcwd -- called from module sr_port/setzdir.c at line 70
  %YDB-I-TEXT, No such file or directory
  ```

* Turns out it is a regression introduced in a prior commit (acb8b27).
  Before that commit, ydbinstall.sh did a `rm -rf $tmpdir` at the end of the script once it knew YottaDB
  was successfully installed. But as part of that commit, code was added to install the plugins (if they
  were specified as part of the ydbinstall.sh command line) AFTER the location where the `rm -rf $tmpdir`
  happened. And each plugin installation had a `ydb_env_set` invocation to start with.

  Because of the `rm -rf $tmpdir`, each of these `ydb_env_set` invocations happened in a non-existent
  directory. And this is the source of the `getcwd()` failure and the resultant `YDB-E-SYSCALL` errors.

* This is now fixed by moving the `rm -rf $tmpdir` to the new end of the ydbinstall.sh script AFTER the
  plugin install code. Each plugin install records whether it succeeded or not. If any plugin install
  fails, the `rm -rf $tmpdir` is not done at the end. If all plugin installs succeed, only then is it done.

* In addition, the exit status of ydbinstall.sh is now fixed to be 0 if all plugin installs succeed and
  1 (a non-zero value) if at least one plugin install failed.

* Fixed a sh syntax error in a `"default" = $ydb_icu_version` check. Surrounded the `$ydb_icu_version`
  usage in double-quotes. Or else one got a `./ydbinstall.sh: 896: [: =: argument expected` error.

sr_unix/ydbinstall.sh

@@ -756,7 +756,11 @@ if [ "Y" = "$gtm_dryrun" ] ; then echo Installation prepared in $gtm_tmpdir ; ex
 
 sh -x ./configure.sh <$gtm_configure_in 1> $gtm_tmpdir/configure_${timestamp}.out 2>$gtm_tmpdir/configure_${timestamp}.err
 if [ $? -gt 0 ] ; then echo "configure.sh failed. Output follows"; cat $gtm_tmpdir/configure_${timestamp}.out $gtm_tmpdir/configure_${timestamp}.err ; exit 1; fi
-rm -rf $tmpdir	# Now that install is successful, remove temporary directory
+
+rm -rf $tmpdir/*	# Now that install is successful, remove everything under temporary directory
+			# We might still need this temporary directory for installing optional plugins (encplugin, posix etc.)
+			# if they have been specified in the ydbinstall.sh command line. Not having a valid current directory
+			# will cause YDB-E-SYSCALL errors from "getcwd()" in ydb_env_set calls made later.
 if [ "Y" = "$gtm_gtm" ] ; then
 	product_name="GT.M"
 else
@@ -810,7 +814,11 @@ fi
 
 # install optional components if they were selected
 
+remove_tmpdir=1	# It is okay to remove $tmpdir at the end assuming ydbinstall is successful at installing plugins.
+		# Any errors while installing any plugin will set this variable to 0.
+
 if [ "Y" = $ydb_posix ] ; then
+	cd $tmpdir	# Get back to top level temporary directory as the current directory for ydb_env_set
 	. ${ydb_installdir}/ydb_env_set
 	mkdir posix_tmp
 	cd posix_tmp
@@ -837,14 +845,18 @@ if [ "Y" = $ydb_posix ] ; then
 		sudo rm -R posix_tmp
 	elif ["0" != $status -a "0" != $status_utf8] ; then
 		echo "POSIX plugin build failed in both M and UTF8 modes. The build directory ($PWD/posix_tmp) has been saved."
+		remove_tmpdir=0
 	elif ["0" != $status] ; then
 		echo "POSIX plugin build failed in M mode. The build directory ($PWD/posix_tmp) has been saved."
+		remove_tmpdir=0
 	else
 		echo "POSIX plugin build failed in UTF8 mode. The build directory ($PWD/posix_tmp) has been saved."
+		remove_tmpdir=0
 	fi
 fi
 
 if [ "Y" = $ydb_encplugin ] ; then
+	cd $tmpdir	# Get back to top level temporary directory as the current directory for ydb_env_set
 	export ydb_icu_version=$ydb_icu_version
 	mkdir enc_tmp
 	cd enc_tmp
@@ -858,13 +870,15 @@ if [ "Y" = $ydb_encplugin ] ; then
 		sudo rm -R enc_tmp
 	else
 		echo "Encryption plugin build failed. The build directory ($PWD/enc_tmp) has been saved."
+		remove_tmpdir=0
 	fi
 	# rename gtmcrypt to ydbcrypt and create a symbolic link for backward compatibility
 	mv ${ydb_installdir}/plugin/gtmcrypt ${ydb_installdir}/plugin/ydbcrypt
 	ln -s ${ydb_installdir}/plugin/ydbcrypt ${ydb_installdir}/plugin/gtmcrypt
 fi
 
 if [ "Y" = $ydb_zlib ] ; then
+	cd $tmpdir	# Get back to top level temporary directory as the current directory for ydb_env_set
 	. ${ydb_installdir}/ydb_env_set
 	mkdir zlib_tmp
 	cd zlib_tmp
@@ -879,7 +893,7 @@ if [ "Y" = $ydb_zlib ] ; then
 	sudo cp _ZLIB.m ${ydb_installdir}/plugin/r
 	${ydb_installdir}/mumps ${ydb_installdir}/plugin/r/_ZLIB
 	if [ "Y" = $ydb_utf8 ] ; then
-		if [ "default" = $ydb_icu_version ] ; then
+		if [ "default" = "$ydb_icu_version" ] ; then
 			ydb_icu_version=`pkg-config --modversion icu-io`
 		fi
 		mkdir utf8
@@ -898,10 +912,12 @@ if [ "Y" = $ydb_zlib ] ; then
 		sudo rm -R zlib_tmp
 	else
 		echo "zlib plugin build failed. The build directory ($PWD/zlib_tmp) has been saved."
+		remove_tmpdir=0
 	fi
 fi
 
 if [ "Y" = $ydb_octo ] ; then
+	cd $tmpdir	# Get back to top level temporary directory as the current directory for ydb_env_set
 	export ydb_dist=${ydb_installdir}
 	curl -fSsLO https://gitlab.com/YottaDB/DBMS/YDBOcto/-/archive/master/YDBOcto-master.tar.gz
 	tar xzf YDBOcto-master.tar.gz
@@ -923,5 +939,11 @@ if [ "Y" = $ydb_octo ] ; then
 		sudo rm YDBOcto-master.tar.gz
 	else
 		echo "Octo build failed. The build directory ($PWD/YDBOcto-master) and the tarball ($PWD/YDBOcto-master.tar.gz) have been saved."
+		remove_tmpdir=0
 	fi
 fi
+
+if [ 0 = "$remove_tmpdir" ] ; then exit 1; fi	# error seen while installing one or more plugins
+
+rm -rf $tmpdir	# Now that we know it is safe to remove $tmpdir, do that before returning normal status
+exit 0