关于Eclipse合并工具覆盖本地变更及差异显示异常的咨询

Let me break down what's going on here and how to fix these frustrating issues—you’re definitely not alone in hitting these quirks!

Why Your Local Changes Are Being Overwritten #

The behavior where clicking Copy all non conflicting changes from right to left overwrites your gray-marked local changes is almost always a bug in how Eclipse’s merge tool identifies and applies "non-conflicting" changes in older versions. Here’s the breakdown:

• In some releases (like Mars, Neon, and early Oxygen builds), the tool’s logic for this button is flawed—it may misinterpret line context differences as conflicts, or even replace the entire left pane with the right instead of merging only non-conflicting bits.
• This is a well-documented issue that’s been addressed in more recent Eclipse updates.

Fixes to Try: #

• Update Eclipse first: Grab the latest stable release (e.g., 2023-09 or newer). Most of these merge tool bugs have been patched in recent builds.
• Skip the problematic button temporarily: Instead of using the one-click bulk copy, use Copy current change from right to left to apply individual non-conflicting changes, or manually copy lines over.
• Switch to an external merge tool: Configure Eclipse to use a third-party tool like Beyond Compare or KDiff3 for more reliable logic. Head to Window > Preferences > Team > Git > Merge Tools to set this up.

Why False Diff Markers Stick Around #

The lingering gray/blue diff indicators even after merging are almost always a cache or UI sync issue:

• The merge tool doesn’t automatically refresh the file’s state after you apply changes, so the UI keeps showing old diff metadata.
• Sometimes your workspace’s resource cache gets out of sync with the actual file content.

Fixes to Try: #

• Refresh the file: Right-click the conflicting file > Team > Refresh (or press F5) to force Eclipse to recheck the file’s content.
• Restart the merge tool: Close the merge window and reopen it—this clears the tool’s local state.
• Clean your workspace: Go to Project > Clean..., select your project, and let Eclipse rebuild it to fix stale cache issues.
• Restart Eclipse: If all else fails, a quick restart usually flushes any lingering UI cache.

Is This a Known Bug? #

Yes! Both issues have been reported by multiple users in Eclipse’s bug tracker. The overwrite bug was resolved in later releases, and the false diff marker issue is a recurring UI sync problem that pops up occasionally across versions. Updating to the latest Eclipse build is the most reliable way to fix both.

内容的提问来源于stack exchange，提问作者Oliver Watkins