The primary evidence for the vulnerable function imagetotga comes directly from the vulnerability title and description, as well as the linked GitHub issue #858. The issue includes an Address Sanitizer (ASan) log that clearly indicates a heap-buffer-overflow within this function during the processing of a J2K file. Although a specific fixing commit was not found through the provided tools and initial search, the consistent reporting across multiple sources (vulnerability description, GitHub issue, ASan log) provides high confidence in identifying imagetotga as the vulnerable function. The vulnerability occurs in convert.c within the OpenJPEG library.