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IDProjectCategoryView StatusLast Update
0003140Ham Radio DeluxeBugpublic2019-02-24 15:12
ReporterK7ZCZAssigned ToK7ZCZ 
Status closedResolutionfixed 
Product Version6.5.0.188 
Target VersionFixed in Version6.5.0.196 
Summary0003140: SystemTimeTotimet() copy-paste function is broken
DescriptionThere's a SystemTimeTotimet() function floating around the code base which has a bogus implemnetation. It converts the time represented by a Windows SYSTEMTIME structure to a CRTL time_t value.

It's meant to initialize a struct tm, then give that to mktime(), and use the resulting time_t value. But it doesn't work correctly; it fails to initialize the tm's is_dst field. The structure is held on the stack, so the value is random. Which means the result is off by an hour randomly.

The function is used to convert local time to UTC (or back), and will adversely affect the reuslts of such a computation at random. The algorithm (more copy pasta in its implementation) is to call the Windows GetSystemTime() API, then the GetLocalTime() API, convert the values to time_t, and then subtract the difference.

Statistically, the values will be correct half the time (+0 +0 corect, and +1 +1 compensating errors). But since the calling locations introduce bias in how they used the previous stack space entries, then the results have some deterministic factor and might not be completely random.

The subtraction algorithm is absurd, anyway. If there's a clock tick between the Windows get time calls, the difference won't be an exact amount -- off by a second or even two.

A correct implementation calls the Windows GetTimeZoneInformation API and uses the time zone bias value it returns, directly, without any computation or conversion.
Steps To ReproduceReview the code
Additional InformationSatellite Tracker and Logbook contain copies of this
TagsNo tags attached.
Testing Beta Successful


related to 0001564 closedWA9PIE Ham Radio Deluxe Line in "Next Passes" no longer follows the satellite across the horizon 
related to 0003090 closedK7ZCZ Ham Radio Deluxe Time shown below each of the passes in the "Next Passes" pane are off by 60 minutes late 
related to 0002958 closedKB3NPH Ham Radio Deluxe Spotted stations not appearing in Bandmap 



2019-01-30 23:06

administrator   ~0007176

fixed with this checkin:


2019-01-31 08:39

administrator   ~0007179

Tweaked with this checkin:


2019-01-31 23:06

administrator   ~0007187

I'm going to say this is fixed and is validated.

That did change things a bit for 3090, but makes them easier to replicate (in my opinion).

Now the problem is 3090 where the graph is always showing local time in 24 hr format when it should follow what's been selected in time format (as it does above the graph). I've added notes to 3090.


2019-02-01 14:33

administrator   ~0007202

This code was treating the bias as minutes; I've fixed it to convert to seconds as necessary. Done in this checkin:

Issue History

Date Modified Username Field Change
2019-01-30 20:43 K7ZCZ New Issue
2019-01-30 20:44 K7ZCZ Relationship added related to 0003090
2019-01-30 22:15 K7ZCZ Relationship added related to 0002958
2019-01-30 23:06 K7ZCZ Assigned To => K7ZCZ
2019-01-30 23:06 K7ZCZ Status new => resolved
2019-01-30 23:06 K7ZCZ Resolution open => fixed
2019-01-30 23:06 K7ZCZ Note Added: 0007176
2019-01-30 23:14 WA9PIE Relationship deleted related to 0002958
2019-01-30 23:14 WA9PIE Relationship added related to 0001564
2019-01-31 08:39 K7ZCZ Note Added: 0007179
2019-01-31 15:16 K7ZCZ Relationship added related to 0002958
2019-01-31 23:06 WA9PIE Status resolved => closed
2019-01-31 23:06 WA9PIE Fixed in Version =>
2019-01-31 23:06 WA9PIE Summary SystemTimeTotimet() copy-pasta function is broken => SystemTimeTotimet() copy-paste function is broken
2019-01-31 23:06 WA9PIE Description Updated View Revisions
2019-01-31 23:06 WA9PIE Testing Not Started => Beta Successful
2019-01-31 23:06 WA9PIE Note Added: 0007187
2019-02-01 14:33 K7ZCZ Note Added: 0007202
2019-02-24 14:40 WA9PIE Fixed in Version =>
2019-02-24 15:12 WA9PIE Project 3 - Current Dev List => Ham Radio Deluxe