x/tools/gopls: sigpanic in methods of persistent.Map (corrupt g)

[adonovan]

#!stacks
"sigpanic" &&
  ("persistent.union:+0,+0x0" ||/* union */
   "persistent.(*mapNode).forEach:+0,+0x0")  

Issue created by stacks.

TEXT golang.org/x/tools/gopls/internal/util/persistent.union(SB) /Users/adonovan/go/pkg/mod/golang.org/x/tools/gopls@v0.19.1/internal/util/persistent/map.go
  map.go:222            0x100762760             f9400b90                MOVD 16(R28), R16                   <---- panic
  map.go:222            0x100762764             eb3063ff                CMP R16, RSP                                                                         
  map.go:222            0x100762768             540017e9                BLS 191(PC)                                                                          
  ...

TEXT golang.org/x/tools/gopls/internal/util/persistent.(*mapNode).forEach(SB) /Users/adonovan/go/pkg/
mod/golang.org/x/tools/gopls@v0.19.1/internal/util/persistent/map.go
  map.go:171            0x1007626c0             f9400b90                MOVD 16(R28), R16        <--- panic
  map.go:171            0x1007626c4             eb3063ff                CMP R16, RSP            
  map.go:171            0x1007626c8             54000429                BLS 33(PC)              
  ...                                                        

This stack C2gvcQ was reported by telemetry:

• crash/crash
• runtime.throw:+9,+0x37
• runtime.sigpanic:+33,+0x223
• golang.org/x/tools/gopls/internal/util/persistent.union:+0,+0x0
• golang.org/x/tools/gopls/internal/util/persistent.(*Map[...]).Set:+3,+0x14b
• golang.org/x/tools/gopls/internal/cache.(*fileMap).set:+1,+0x4f
• golang.org/x/tools/gopls/internal/cache.(*fileMap).clone:+26,+0x34b
• golang.org/x/tools/gopls/internal/cache.(*Snapshot).clone:+27,+0x33b
• golang.org/x/tools/gopls/internal/cache.(*Session).invalidateViewLocked:+25,+0x1c7
• golang.org/x/tools/gopls/internal/cache.(*Session).DidModifyFiles:+158,+0xd7f
• golang.org/x/tools/gopls/internal/server.(*server).didModifyFiles:+36,+0x317
• golang.org/x/tools/gopls/internal/server.(*server).DidChangeWatchedFiles:+13,+0x1fb
• golang.org/x/tools/gopls/internal/protocol.serverDispatch:+634,+0x5437
• golang.org/x/tools/gopls/internal/lsprpc.(*streamServer).ServeStream.ServerHandler.func4:+5,+0x73
• golang.org/x/tools/gopls/internal/lsprpc.(*streamServer).ServeStream.handshaker.func5:+52,+0x68f
• golang.org/x/tools/gopls/internal/protocol.Handlers.MustReplyHandler.func1:+2,+0xbf
• golang.org/x/tools/gopls/internal/protocol.Handlers.AsyncHandler.func2.2:+3,+0x8f

golang.org/x/tools/gopls@v0.19.1 go1.24.4 darwin/arm64 other (1)

Dups: q291Zg

[adonovan]

This stack q291Zg was reported by telemetry:

• crash/crash
• runtime.throw:+9,+0x37
• runtime.sigpanic:+33,+0x223
• golang.org/x/tools/gopls/internal/util/persistent.(*mapNode).forEach:+0,+0x0
• golang.org/x/tools/gopls/internal/cache.(*Snapshot).reloadWorkspace.(*Map[...]).All.func1:=165,+0x117
• golang.org/x/tools/gopls/internal/cache.(*Snapshot).reloadWorkspace:+8,+0xb8
• golang.org/x/tools/gopls/internal/cache.(*Snapshot).awaitLoaded:+3,+0x37
• golang.org/x/tools/gopls/internal/cache.(*Snapshot).WorkspaceMetadata:+1,+0x43
• golang.org/x/tools/gopls/internal/server.(*server).diagnose:+68,+0x2ef
• golang.org/x/tools/gopls/internal/server.(*server).diagnoseSnapshot:+31,+0x1d7
• golang.org/x/tools/gopls/internal/server.(*server).diagnoseChangedViews.func1:+3,+0xbb
• golang.org/x/tools/gopls/internal/server.(*server).diagnoseChangedViews.gowrap1:+16,+0x3b
• runtime.goexit:+0,+0x3

golang.org/x/tools/gopls@v0.19.1 go1.24.4 darwin/arm64 other (1)

[gabyhelp]

Related Issues

• x/tools/gopls: sigpanic in persistent.(*mapNode).forEach (bad SP) #71115
• x/tools/gopls: impossible crash in persistent.Map decref #72931
• x/tools/gopls: nil deref in x/telemetry/internal/counter.(*Counter).add #73890
• x/tools/gopls: Implementation (by signatures): nil panic in dynamicFuncCallType #74305 (closed)
• x/tools/gopls: Definition: crash on [unsafe.Pointer] doc link #74434 (closed)
• x/tools/gopls: SEGV in HasSuffix (corrupt string) #74348
• x/tools/gopls: template.SemanticTokens: panic in template.(*Parsed).RuneCount #74776 (closed)
• x/tools/gopls: SIGBUS incrementing telemetry counter #74651
• x/tools/gopls: DidCreateFiles: panic in Files[i].URI.Clean() #74652
• x/tools/gopls: CodeActions: "end < start" panic #74394 (closed)

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