[check] Fail on multiply defined labels

Author: jensmaurer

tools/check-output.sh

@@ -17,6 +17,9 @@ sed -n '/\.tex/{s/^.*\/\([-a-z0-9]\+\.tex\).*$/\1/;h};
 /Overfull [\\][hv]box\|LaTeX Warning..Reference/{x;p;x;p}' std.log |
     sed '/^.\+\.tex$/{N;s/\n/:/}' | fail || failed=1
 
+grep "Label .* multiply defined" std.log |
+    fail || failed=1
+
 # Check for dangling "see" in general index (does not work with formatting)
 grep item < std-generalindex.ind | sed 's/,.*$//;s/\\[sub]*item //' |
     awk '/^  [^ ]/ { item=$0; print $0 }  /^    [^ ]/ { subitem=$0; print item ", " $0 } /^      [^ ]/ { print item ", " subitem ", " $0 }' |