test00_specsyntax.in: add curl check for URL; automatic replace if redirect, error if url not orking (response code != 200)

tests/test00_specsyntax.in

@@ -42,6 +42,30 @@ function specfile.checksyntax() {
 
    local total_issues=0
 
+   # 0. checking if 'Source[0]' is a valid internet address
+   # (skip this test if no '%setup' section has been found)
+   test.skip $test_number || {
+      notify.note "$(test.num2str). ${NOTE}"\
+"url""${NORM}..."
+     if [[ "$SPEC_URL" ]]; then
+       http_code=`curl -s -o /dev/null -w "%{http_code}" $SPEC_URL`
+       if [ "$http_code" != "200" ]; then
+         if [ "${http_code:0:2}" == "30" ]; then
+           http_effective_url=`curl -w "%{url_effective}" -I -L -s -o /dev/null -S $SPEC_URL`
+           { notify.warning "\
+\`url': "$"redirect detected: replacing from \`$SPEC_URL' to \`${http_effective_url}'"
+                  let "total_issues += 1";
+           }
+           sed -i "s|^\(URL:[[:space:]]*\)$SPEC_URL.*|\1${http_effective_url}|" $specfile
+         else
+           { notify.error "\
+\`url': "$"invalid return code for \`$SPEC_URL': $http_code"
+                  let "total_issues += 1"; }
+         fi
+       fi
+     fi; }
+   test_number=$(($test_number + 1))
+
    # 1. checking if 'Source[0]' is a valid internet address
    # (skip this test if no '%setup' section has been found)
    test.skip $test_number || {