rrddump on RRD file with HW enabled produces out of range HWPREDICT slope values

[bbalen]

RRDTool version 1.4.8 on Oracle Linux Server release 7.4

When I dump an RRD file with HW enabled to XML, occasionally this produces HWPREDICT <slope> and <last_slope> values that are out of range for an rrdtool restore. Sample XML output below.

When I try to restore such an XML file I get this error: ERROR: ling 22804: get_xml_double from '7.9050503335e-323' Numerical result out of range

            <cf>HWPREDICT</cf>
            <pdp_per_row>1</pdp_per_row> <!-- 600 seconds -->

            <params>
            <hw_alpha>1.0000000000e-01</hw_alpha>
            <hw_beta>3.0000000000e-02</hw_beta>
            <dependent_rra_idx>13</dependent_rra_idx>
            </params>
            <cdp_prep>
                    <ds>
                    <primary_value>4.2944348160e+09</primary_value>
                    <secondary_value>4.2944348160e+09</secondary_value>
                    <intercept>4.2944348160e+09</intercept>
                    <last_intercept>4.2944348160e+09</last_intercept>
                    <slope>0.0000000000e+00</slope>
                    <last_slope>0.0000000000e+00</last_slope>
                    <nan_count>1</nan_count>
                    <last_nan_count>1</last_nan_count>
                    </ds>
                    <ds>
                    <primary_value>3.2212254720e+09</primary_value>
                    <secondary_value>3.2212254720e+09</secondary_value>
                    <intercept>3.2212254720e+09</intercept>
                    <last_intercept>3.2212254720e+09</last_intercept>
                    <slope>7.9050503335e-323</slope>
                    <last_slope>7.9050503335e-323</last_slope>
                    <nan_count>1</nan_count>
                    <last_nan_count>1</last_nan_count>
                    </ds>
                    <ds>
                    <primary_value>2.6588475710e+09</primary_value>
                    <secondary_value>6.0911664914e+08</secondary_value>
                    <intercept>2.6461472771e+09</intercept>
                    <last_intercept>2.6385320709e+09</last_intercept>
                    <slope>1.8799758300e+06</slope>
                    <last_slope>1.7025975730e+06</last_slope>
                    <nan_count>1</nan_count>
                    <last_nan_count>1</last_nan_count>
                    </ds>
            </cdp_prep>