fix: handle BMP V4/V5 headers in cross-platform clipboard image transfer#1
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hsddszjs wants to merge 7 commits into
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fix: handle BMP V4/V5 headers in cross-platform clipboard image transfer#1hsddszjs wants to merge 7 commits into
hsddszjs wants to merge 7 commits into
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macOS generates BMP data with BITMAPV4HEADER (108 bytes) or BITMAPV5HEADER (124 bytes) for screenshots, but the BMP-to-DIB conversion hardcoded the header size to 40 bytes (BITMAPINFOHEADER). This truncated the header while biSize still indicated 108/124 bytes, causing Windows to read pixel data as header data and display a white/corrupt image. Fix toIClipboard: strip only the 14-byte BMP file header, keeping the entire DIB intact (header + color table + pixel data). Fix fromIClipboard: compute the BMP file pixel offset from the actual DIB header size and color table, instead of hardcoding 54. Applied the same fix to both OSX and XWindows clipboard converters. https://claude.ai/code/session_015Y82naHd7Tuj1inyFJtKmP
When Windows re-reads CF_DIB data with a BITMAPV4HEADER (108 bytes) or BITMAPV5HEADER (124 bytes), the pixel data pointer was calculated incorrectly. The code unconditionally added 3 DWORDs (12 bytes) for BI_BITFIELDS color masks after the header, but V4/V5 headers include these masks within the header itself. This caused srcBits to point 12 bytes past the actual pixel data start, potentially reading past the allocated buffer and crashing the server — which disconnected the macOS client. Fix: only add the extra color mask offset for BITMAPINFOHEADER (biSize == 40), since V4/V5 headers already contain the masks. https://claude.ai/code/session_015Y82naHd7Tuj1inyFJtKmP
When files are copied on macOS (e.g., in Finder), the pasteboard contains file reference data but no native image types. However, macOS's UTI auto-conversion may claim com.microsoft.bmp is available and attempt to convert file references to BMP format. This conversion can hang indefinitely, blocking the client's event loop and causing a keep-alive timeout disconnect from the server. Fix: before checking for bitmap clipboard data, verify that the pasteboard actually contains native image data (public.tiff or public.png). Skip bitmap processing entirely when only file references are present. https://claude.ai/code/session_015Y82naHd7Tuj1inyFJtKmP
Fixes across all platforms for issues that can occur during regular clipboard operations: Windows: - Fix out-of-bounds read in convertLinefeedToUnix when text ends with \r without following \n (check n > 1 before accessing scan[1]) - Fix missing GlobalUnlock when srcSize <= 1 in text converter - Add null checks for GetDC, CreateDIBSection, CreateCompatibleDC in bitmap converter to prevent crash under GDI resource pressure - Add integer overflow protection for large bitmap dimensions (4 * w * h) using 64-bit arithmetic and reasonable size limits - Validate biBitCount range before bit shift in color table calc - Add bounds check for HTML fragment start/end offsets macOS / XWindows: - Validate biSize range (40-1024) in BMP fromIClipboard to prevent reading past buffer with unusual header sizes - Ensure buffer is large enough before reading DIB header fields - Fix CFStringGetBytes buffSize <= 0 not checked before allocation in text and HTML converters (was checking new return instead) Common: - Add bounds checking in IClipboard::unmarshall to prevent reading past buffer end with truncated/corrupt network data - Fix ClipboardChunk::assemble toULong parse error not checked - Fix LOG_ERR format specifier: use %zu for size_t values - Fix StreamChunker infinite loop when size == 0 https://claude.ai/code/session_015Y82naHd7Tuj1inyFJtKmP
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Summary
toIClipboard: strip only the 14-byte BMP file header, keeping the entire DIB intactfromIClipboard: compute pixel offset from actual DIB header metadata instead of hardcoding 54Test plan
https://claude.ai/code/session_015Y82naHd7Tuj1inyFJtKmP