tokenizeLineToHTML() misaligns tabs when startOffset > 0 #263386
Description
Type: Bug
When startOffset is non-zero, tabsCharDelta doesn't accumulate chars before charIndex, and the first <span> ends up short on padding in generated HTML.
This causes clipboardCopyWithSyntaxHighlightingAction command to return incorrect padding on the first line in its output if we start selection with text after the first column.
Source location:
src/vs/editor/common/languages/textToHtmlTokenizer.ts
VS Code version: Code - OSS Dev 1.104.0 (Commit 0a565d1, Date Mon Aug 25 23:41:01 2025 -0700)
OS version: Linux x64 6.14.0-28-generic
Modes:
System Info
| Item | Value |
|---|---|
| CPUs | 13th Gen Intel(R) Core(TM) i9-13900KF (32 x 5497) |
| GPU Status | 2d_canvas: enabled direct_rendering_display_compositor: disabled_off_ok gpu_compositing: enabled multiple_raster_threads: enabled_on opengl: enabled_on rasterization: enabled raw_draw: disabled_off_ok skia_graphite: disabled_off trees_in_viz: disabled_off video_decode: enabled video_encode: disabled_software vulkan: disabled_off webgl: enabled webgl2: enabled webgpu: disabled_off webnn: disabled_off |
| Load (avg) | 1, 1, 1 |
| Memory (System) | 62.62GB (41.07GB free) |
| Process Argv | . --disable-extension=vscode.vscode-api-tests --no-sandbox |
| Screen Reader | no |
| VM | 0% |
| DESKTOP_SESSION | ubuntu |
| XDG_CURRENT_DESKTOP | Unity |
| XDG_SESSION_DESKTOP | ubuntu |
| XDG_SESSION_TYPE | x11 |