{"record":{"id":"8752a30b7b73a80d","repo":"xai-org/grok-build","slug":"rgba-buffer-too-short-expected-at-least-bytes","errorCode":null,"errorMessage":"RGBA buffer too short: expected at least {} bytes for {}x{}, got {}","messagePattern":"RGBA buffer too short: expected at least (.+?) bytes for (.+?)x(.+?), got (.+?)","errorType":"validation","errorClass":null,"httpStatus":null,"severity":"error","filePath":"crates/codegen/xai-grok-shared/src/clipboard.rs","lineNumber":2196,"sourceCode":"        #[cfg(not(target_os = \"linux\"))]\n        {\n            let _ = path;\n            anyhow::bail!(\"image clipboard not supported on this platform\")\n        }\n    }\n\n    /// Encode raw RGBA pixels into PNG bytes.\n    pub(super) fn encode_rgba_to_png(\n        rgba: &[u8],\n        width: u32,\n        height: u32,\n    ) -> anyhow::Result<Vec<u8>> {\n        use image::codecs::png::PngEncoder;\n        use image::{ColorType, ImageEncoder};\n\n        let expected_len = (width as usize) * (height as usize) * 4;\n        if rgba.len() < expected_len {\n            anyhow::bail!(\n                \"RGBA buffer too short: expected at least {} bytes for {}x{}, got {}\",\n                expected_len,\n                width,\n                height,\n                rgba.len()\n            );\n        }\n\n        let mut png_buf = Vec::with_capacity(expected_len / 4);\n        let encoder = PngEncoder::new(&mut png_buf);\n        encoder.write_image(rgba, width, height, ColorType::Rgba8.into())?;\n        Ok(png_buf)\n    }\n\n    pub fn get_attachments() -> anyhow::Result<super::ClipboardAttachments> {\n        // `ContentNotAvailable` is already Ok(None); other file_list errors must\n        // not skip get_image when a raster is still present.\n        let file_urls = match get_file_urls() {","sourceCodeStart":2178,"sourceCodeEnd":2214,"githubUrl":"https://github.com/xai-org/grok-build/blob/bc7f02eddd3d84085849dc19ed216f11c23b0571/crates/codegen/xai-grok-shared/src/clipboard.rs#L2178-L2214","documentation":"encode_rgba_to_png validates that the RGBA pixel buffer holds at least width * height * 4 bytes before PNG-encoding it. A shorter buffer would produce a truncated/corrupt image, so the function bails with the expected and actual sizes.","triggerScenarios":"Calling encode_rgba_to_png(rgba, width, height) where rgba.len() < width * height * 4 — e.g. passing a buffer captured from a screen region whose dimensions were recomputed after the buffer was captured.","commonSituations":"Screen-capture code that resizes the width/height after grabbing pixels; off-by-one or stride mismatches (buffer sized for width*height*3 RGB); DPI-scaled captures where logical vs physical pixels differ.","solutions":["Size the buffer as width * height * 4 before capture, or re-capture after the dimensions are final.","Verify whether the source data is RGB (3 bytes/px) and convert to RGBA before encoding.","Recompute width/height from the actual buffer length (len / 4) instead of passing stale values."],"exampleFix":"// before\nlet png = encode_rgba_to_png(&rgba, new_w, new_h)?;\n// after\nlet expected = new_w as usize * new_h as usize * 4;\nassert_eq!(rgba.len(), expected, \"RGBA buffer/dimension mismatch\");\nlet png = encode_rgba_to_png(&rgba, new_w, new_h)?;","handlingStrategy":"validation","validationCode":"fn validate_rgba_buffer(rgba: &[u8], width: u32, height: u32) -> Result<(), String> {\n    let expected = width as usize * height as usize * 4;\n    if rgba.len() < expected {\n        return Err(format!(\"RGBA buffer too short: need {expected}, have {}\", rgba.len()));\n    }\n    Ok(())\n}\n// call before encode_rgba_to_png\nvalidate_rgba_buffer(&rgba, w, h)?;","typeGuard":null,"tryCatchPattern":"match encode_rgba_to_png(&rgba, w, h) {\n    Ok(png) => png,\n    Err(e) if e.to_string().starts_with(\"RGBA buffer too short\") => {\n        // recover: recompute dims from buffer length\n        let len = rgba.len() / 4;\n        encode_rgba_to_png(&rgba, (len / row_len) as u32, row_len as u32)?\n    }\n    Err(e) => return Err(e),\n}","preventionTips":["Compute buffer size from the same width/height values you pass to the encoder","Re-verify dimensions after any resize/scale step before encoding","Use checked multiplication (width as usize).checked_mul(height).and_then(|v| v.checked_mul(4))","Confirm pixel format is RGBA (4 bytes/px), not RGB (3 bytes/px)"],"tags":["image","png","buffer-size","validation"],"backgroundTag":"buffer-size-mismatch","analyzedSha":"bc7f02eddd3d84085849dc19ed216f11c23b0571","analyzedAt":"2026-08-31T04:59:42.031Z","schemaVersion":2},"datasetVersion":"2026-08-31T09:17:48.483Z"}