I don't contribute much to open source, mostly due to employment agreements, but a couple I was able to make:
1. Bulk copying null values with Python Sybase module (initialized variable used)
2. ACE high res timer bug under x64. Inline ASM was using the wrong registers in x64 mode (reading garbage upper 32 bits of 64 bit value).
Both of these were bizarre bugs, and neither was immediately evident.
#1 was presented by an error saying something to the effect of "received xXxX bytes, expecting yyyy".
#2 was harder. It became evident because of logging. The high res timer was used gor logging amd intermittently, I was seeing +200 years supposedly elapsed during a db operation. Obviously wrong. It was a bug due to how registers are handled between x86 and x64 code.
Both of these were bizarre bugs, and neither was immediately evident.
#1 was presented by an error saying something to the effect of "received xXxX bytes, expecting yyyy".
#2 was harder. It became evident because of logging. The high res timer was used gor logging amd intermittently, I was seeing +200 years supposedly elapsed during a db operation. Obviously wrong. It was a bug due to how registers are handled between x86 and x64 code.