Fail gracefully when there's an error computing a pkg repo version.

Sometimes sbopkg can't determine the version of a package. For example,
the google-chrome script looks at the source archive to determine it, and
such archive can very well be unavailable.
This patch makes sbopkg intercept the error condition and notify it to
the user gracefully, while at the same time falling back to trusting the
version provided in the .info file.
Thanks to alkos333 for the bug report.

Signed-off-by: Mauro Giachero <mauro.giachero@gmail.com>

ChangeLog-current.txt

@@ -20,4 +20,8 @@ enhancements:
     artourter for the report.
   * Modify links in check_for_latest() function to use new sbopkg.org
     redirects.
+  * Prevent sbopkg from spitting error messages when trying to determine the
+    version of some packages (e.g. google-chrome, whose version is discovered
+    looking into the source package which can be missing). Thanks to alkos333
+    for the bug report.
 +--------------------------+

src/usr/doc/KNOWN_ISSUES

@@ -15,3 +15,13 @@ tools it uses:
   Details: http://code.google.com/p/sbopkg/issues/detail?id=30
 
   Workaround: use dialog's own exit methods - its buttons, escape, ^C, etc.
+
+* when checking for updates, for some packages Sbopkg may tell you
+  "Note: repo version not obtainable by standard method, may be inaccurate.".
+  This happens with packages whose version is very difficult/impossible to
+  determine without actually building the package -- one example of this at
+  the time of writing is the google-chrome package, whose version is picked
+  from the source archive itself. In these cases sbopkg falls back to trusting
+  the .info file, and warns the user about it.
+
+  Workaround: none needed

src/usr/sbin/sbopkg

@@ -637,6 +637,7 @@ check_for_updates() {
     # Giachero for this much-improved update code and related functions!
 
     local TEMPFILE=$SBOPKGTMP/sbopkg_updates_tempfile
+    local ERRORMSG=$SBOPKGTMP/sbopkg_updates_errormsg
     local NEWSB NEWINFO NEWVER
     local VERSION_EXPRESSION
     local UPDATELIST VERSION_FILE PROGRESSBAR_INTERRUPTED
@@ -657,7 +658,7 @@ check_for_updates() {
     # Check to see if there are any updates to installed SBo pkgs.
     check_if_repo_exists
     UPDATELIST=$SBOPKGTMP/sbopkg_updatelist
-    rm -f $UPDATELIST
+    rm -f $UPDATELIST $ERRORMSG
     cd /var/log/packages
     PKGS=$(ls *$REPO_TAG 2> /dev/null)
     NUMPKGS=$(wc -w <<< "$PKGS")
@@ -737,19 +738,20 @@ check_for_updates() {
 
                 # Step 3 - reverse the file order
                 # Because dependencies must be first...
-                tac $VERSION_FILE > $TEMPFILE
+                tac $VERSION_FILE >> $TEMPFILE
                 mv $TEMPFILE $VERSION_FILE
 
                 # Step 4 - let's get the version number!
                 # Also, strip any residual program name token.
-                NEWVER=$(sh $VERSION_FILE | rev | cut -d- -f1 | rev)
+                NEWVER=$(sh $VERSION_FILE 2> $ERRORMSG | sed 's/.*-//g')
                 rm -f $VERSION_FILE
 
                 # Step 5 - fixup braindead cases
                 # Sometimes the above doesn't work -- see cpan2tgz for 12.1
                 # In that case, let's trust the .info file...
-                if [[ -z $NEWVER ]]; then
-                    NEWINFO=$(echo $NEWSB | rev | cut -d. -f2- | rev).info
+                [[ -z $NEWVER ]] && echo "Empty version!" >> $ERRORMSG
+                if [[ $(< $ERRORMSG) ]]; then
+                    NEWINFO=$(sed 's/\.SlackBuild$/\.info/g' <<< "$NEWSB")
                     NEWVER=$(grep "^VERSION" $NEWINFO | cut -d\" -f2)
                 fi
 
@@ -808,12 +810,17 @@ check_for_updates() {
                         echo "  No update." >> $UPDATELIST
                     fi
                 fi
+                if [[ $(< $ERRORMSG) ]]; then
+                    echo "  Note: repo version not obtainable by" \
+                        "standard method, may be inaccurate." >> $UPDATELIST
+                fi
             else
                 if [[ $DEBUG -ge 1 ]]; then
                     echo $NAME: >> $UPDATELIST
                     echo "  Not in the repository." >> $UPDATELIST
                 fi
             fi
+            rm -f $ERRORMSG
 
             # Progress indicator, for the progressbar
             (( PROGRESSCOUNTER += 1 ))
@@ -1542,9 +1549,9 @@ queue_dir_lister() {
         -maxdepth 1 | sed -e 's/.sqf//' | sort > $QFM
     if [[ -z $(< $QFM) ]]; then
         if [[ $DIAG ]]; then
-            rm -f $QFM
             dialog --title "ERROR" --msgbox "$(crunch "The queue directory \
                 $QUEUEDIR is empty.")" 8 30
+            rm -f $QFM
             return 1
         fi
     fi