Sanity-check the output of 'paper'

bin/pdfjam

@@ -198,16 +198,22 @@ preamble=''                ##  Default LaTeX preamble string.
 ##
 ##  Get default paper size from libpaper >= 2 if possible, otherwise guess A4
 ##
+paperspec=
 if command -v paper >/dev/null ; then
     paperspec=$(paper)
-    paperdimensions=$(echo "$paperspec" | cut -f 2 -d " ")
-    paperunit=$(echo "$paperspec" | cut -f 3 -d " ")
-    if test "$paperunit" = "pt"; then paperunit=bp; fi
-    paperwidth=$(echo "$paperdimensions" | cut -f 1 -d "x")
-    paperheight=$(echo "$paperdimensions" | cut -f 2 -d "x")
-    papersize="papersize={$paperwidth$paperunit,$paperheight$paperunit}"
-    paper='' ## We might not have a LaTeX-compatible name
-else
+    if echo "$paperspec" | grep -q '^.*: '; then
+	paperdimensions=$(echo "$paperspec" | cut -f 2 -d " ")
+	paperunit=$(echo "$paperspec" | cut -f 3 -d " ")
+	if test "$paperunit" = "pt"; then paperunit=bp; fi
+	paperwidth=$(echo "$paperdimensions" | cut -f 1 -d "x")
+	paperheight=$(echo "$paperdimensions" | cut -f 2 -d "x")
+	papersize="papersize={$paperwidth$paperunit,$paperheight$paperunit}"
+	paper='' ## We might not have a LaTeX-compatible name
+    else
+	echo "The 'paper' program seems not to be working; not using it"
+    fi
+fi
+if test -z "$paperspec"; then
     paper='a4paper'  ## fallback paper size is ISO A4
     papersize=''     ## clear papersize
 fi