Fix a deadlock when setting timers <30s before even hours

Author: lhecker

README.md

@@ -4,7 +4,7 @@ This application allows you to automatically switch between light and dark mode
 
 ## Installation
 
-* Download it here: https://github.com/lhecker/windows-dark-mode-switcher/releases/tag/v0.1.2
+* Download it here: https://github.com/lhecker/windows-dark-mode-switcher/releases/tag/v0.1.3
 * Unzip the archive
 * Put `dark-mode-switcher.exe` into this directory:
   ```

src/resource.rc

@@ -147,10 +147,10 @@ BEGIN
         BEGIN
             VALUE "CompanyName", "Leonard Hecker <leonard@hecker.io>"
             VALUE "FileDescription", "https://github.com/lhecker/windows-dark-mode-switcher/"
-            VALUE "FileVersion", "0.1.2.0"
+            VALUE "FileVersion", "0.1.3.0"
             VALUE "LegalCopyright", "MIT License"
             VALUE "ProductName", "Dark Mode Switcher"
-            VALUE "ProductVersion", "0.1.2.0"
+            VALUE "ProductVersion", "0.1.3.0"
         END
     END
     BLOCK "VarFileInfo"

src/suncourse.c

@@ -64,17 +64,15 @@ bool suncourse_is_daytime(float lat, float lon, FILETIME_QUAD* next_update)
 
     // If it's daytime, the next change is the sunset and vice versa.
     double next_h = is_daytime ? ss.sunset : ss.sunrise;
+    // Add 24 hours, because next_h may be negative.
     // Add 30 seconds as wiggle room for the timer.
-    next_h += 30.0 / 3600.0;
-    // Ensure it's [0, 24).
-    next_h = fmod(next_h + 24.0, 24.0);
-
-    double hours;
-    double minutes = modf(next_h, &hours) * 60;
+    long next_min = lround(next_h * 60.0 + 24.0 * 60.0 + 0.5);
+    // Ensure it's [0, 24) hours.
+    next_min = next_min % 1440;
 
     SYSTEMTIME next_st = now_st;
-    next_st.wHour = (WORD)lround(hours);
-    next_st.wMinute = (WORD)lround(minutes);
+    next_st.wHour = (WORD)(next_min / 60);
+    next_st.wMinute = (WORD)(next_min % 60);
     next_st.wSecond = 0;
     next_st.wMilliseconds = 0;