Fix up broken behavior in install-build-deps.sh.

build/install-build-deps.sh

 #!/bin/bash -e
 
 # Script to install everything needed to build chromium (well, ideally, anyway)
 # See http://code.google.com/p/chromium/wiki/LinuxBuildInstructions
 # and http://code.google.com/p/chromium/wiki/LinuxBuild64Bit
 
 install_gold() {
   # Gold is optional; it's a faster replacement for ld,
   # and makes life on 2GB machines much more pleasant.
 
@@ skipping 151 matching lines @@
 fi
 
 sudo apt-get update
 
 # We initially run "apt-get" with the --reinstall option and parse its output.
 # This way, we can find all the packages that need to be newly installed
 # without accidentally promoting any packages from "auto" to "manual".
 # We then re-run "apt-get" with just the list of missing packages.
 echo "Finding missing packages..."
 packages="${dev_list} ${lib_list} ${dbg_list}
-                  $([ "$(uname -m)" = x86_64 ] && echo ${cmp_list})"
-echo "Packages required: $packages"
+                  $([ "$(uname -m)" = "x86_64" ] && echo ${cmp_list})"
+# Intentially leaving $packages unquoted so it's more readable.
+echo "Packages required: " $packages
+echo
 new_list_cmd="sudo apt-get install --reinstall $(echo $packages)"
 if new_list="$(yes n | LANG=C $new_list_cmd)"
 then
+  # We probably never hit this following line.
   echo "No missing packages, and the packages are up-to-date."
 elif [ $? -eq 1 ]
 then
   # We expect apt-get to have exit status of 1.
   # This indicates that we canceled the install with "yes n|".
-  new_list=$(echo $new_list |
+  new_list=$(echo "$new_list" |
     sed -e '1,/The following NEW packages will be installed:/d;s/^  //;t;d')
-  echo "Installing missing packages: $new_list."
-  sudo apt-get install ${new_list}
+  new_list=$(echo "$new_list" | sed 's/ *$//')
+  if [ -z "$new_list" ] ; then
+    echo "No missing packages, and the packages are up-to-date."
+  else
+    echo "Installing missing packages: $new_list."
+    sudo apt-get install ${new_list}
+  fi
+  echo
 else
   # An apt-get exit status of 100 indicates that a real error has occurred.
 
   # I am intentionally leaving out the '"'s around new_list_cmd,
   # as this makes it easier to cut and paste the output
-  echo
   echo "The following command failed: " ${new_list_cmd}
   echo
   echo "It produces the following output:"
   yes n | $new_list_cmd || true
   echo
   echo "You will have to install the above packages yourself."
   echo
   exit 100
 fi
 
@@ skipping 11 matching lines @@
   echo -n "REPLACE SYSTEM LINKER ld with gold and back up ld as ld.orig? (y/N) "
   if yes_no 1; then
     echo "Building binutils."
     install_gold || exit 99
   else
     echo "Not installing gold."
   fi
 esac
 
 # Install 32bit backwards compatibility support for 64bit systems
-if [ "$(uname -m)" = x86_64 ]; then
+if [ "$(uname -m)" = "x86_64" ]; then
   echo "Installing 32bit libraries that are not already provided by the system"
   echo
   echo "While we only need to install a relatively small number of library"
   echo "files, we temporarily need to download a lot of large *.deb packages"
   echo "that contain these files. We will create new *.deb packages that"
   echo "include just the 32bit libraries. These files will then be found on"
   echo "your system in places like /lib32, /usr/lib32, /usr/lib/debug/lib32,"
   echo "/usr/lib/debug/usr/lib32. If you ever need to uninstall these files,"
   echo "look for packages named *-ia32.deb."
   echo "Do you want me to download all packages needed to build new 32bit"
   echo -n "package files (Y/n) "
   if ! yes_no 0; then
     echo "Exiting without installing any 32bit libraries."
     exit 0
   fi
   tmp=/tmp/install-32bit.$$
   trap 'rm -rf "${tmp}"' EXIT INT TERM QUIT
   mkdir -p "${tmp}/apt/lists/partial" "${tmp}/cache" "${tmp}/partial"
   touch "${tmp}/status"
 
   [ -r /etc/apt/apt.conf ] && cp /etc/apt/apt.conf "${tmp}/apt/"
-  cat >>"${tmp}/apt/apt.conf" <<-EOF
+  cat >>"${tmp}/apt/apt.conf" <<EOF
         Apt::Architecture "i386";
         Dir::Cache "${tmp}/cache";
         Dir::Cache::Archives "${tmp}/";
         Dir::State::Lists "${tmp}/apt/lists/";
         Dir::State::status "${tmp}/status";
-        EOF
+EOF
 
   # Download 32bit packages
   echo "Computing list of available 32bit packages..."
   apt-get -c="${tmp}/apt/apt.conf" update
 
   echo "Downloading available 32bit packages..."
   apt-get -c="${tmp}/apt/apt.conf" \
           --yes --download-only --force-yes --reinstall  install \
           ${lib_list} ${dbg_list}
 
@@ skipping 85 matching lines @@
              sed -e 's/[.]so[.][0-9].*/.so/' |
              sort -u); do
     [ "x${i##*/}" = "xld-linux.so" ] && continue
     [ -r "$i" ] && continue
     j="$(ls "$i."* | sed -e 's/.*[.]so[.]\([^.]*\)$/\1/;t;d' |
          sort -n | tail -n 1)"
     [ -r "$i.$j" ] || continue
     sudo ln -s "${i##*/}.$j" "$i"
   done
 fi