Make various goroutines panic-safe

kittens/diff/highlight.go

@@ -32,7 +32,7 @@ var highlighter = sync.OnceValue(func() highlight.Highlighter {
 func highlight_all(paths []string, light bool) {
 	ctx := images.Context{}
 	srd := prefer_light_colors(light)
-	ctx.Parallel(0, len(paths), func(nums <-chan int) {
+	if err := ctx.SafeParallel(0, len(paths), func(nums <-chan int) {
 		for i := range nums {
 			path := paths[i]
 			raw, err := highlighter().HighlightFile(path, &srd)
@@ -45,5 +45,7 @@ func highlight_all(paths []string, light bool) {
 				dark_highlighted_lines_cache.Set(path, text_to_lines(raw))
 			}
 		}
-	})
+	}); err != nil {
+		panic(err)
+	}
 }

kittens/diff/patch.go

@@ -358,14 +358,16 @@ func diff(jobs []diff_job, context_count int) (ans map[string]*Patch, err error)
 		patch        *Patch
 	}
 	results := make(chan result, len(jobs))
-	ctx.Parallel(0, len(jobs), func(nums <-chan int) {
+	if err := ctx.SafeParallel(0, len(jobs), func(nums <-chan int) {
 		for i := range nums {
 			job := jobs[i]
 			r := result{file1: job.file1, file2: job.file2}
 			r.patch, r.err = do_diff(job.file1, job.file2, context_count)
 			results <- r
 		}
-	})
+	}); err != nil {
+		panic(err)
+	}
 	close(results)
 	for r := range results {
 		if r.err != nil {

kittens/diff/search.go

@@ -106,7 +106,7 @@ func (self *Search) search(logical_lines *LogicalLines) {
 	self.matches = make(map[ScrollPos][]Span)
 	ctx := images.Context{}
 	mutex := sync.Mutex{}
-	ctx.Parallel(0, logical_lines.Len(), func(nums <-chan int) {
+	if err := ctx.SafeParallel(0, logical_lines.Len(), func(nums <-chan int) {
 		for i := range nums {
 			line := logical_lines.At(i)
 			if line.line_type == EMPTY_LINE || line.line_type == IMAGE_LINE {
@@ -121,7 +121,9 @@ func (self *Search) search(logical_lines *LogicalLines) {
 				}
 			})
 		}
-	})
+	}); err != nil {
+		panic(err)
+	}
 	for _, spans := range self.matches {
 		slices.SortFunc(spans, func(a, b Span) int { return a.start - b.start })
 	}

tools/tui/download_with_progress.go

@@ -101,6 +101,7 @@ func DownloadFileWithProgress(destpath, url string, kill_if_signaled bool) (err
 	}
 
 	do_download := func() {
+		lp.RecoverFromPanicInGoRoutine()
 		dl_data.mutex.Lock()
 		dl_data.download_started = true
 		dl_data.mutex.Unlock()

tools/tui/graphics/collection.go

@@ -136,14 +136,16 @@ func (self *ImageCollection) ResizeForPageSize(width, height int) {
 
 	ctx := images.Context{}
 	keys := utils.Keys(self.images)
-	ctx.Parallel(0, len(keys), func(nums <-chan int) {
+	if err := ctx.SafeParallel(0, len(keys), func(nums <-chan int) {
 		for i := range nums {
 			img := self.images[keys[i]]
 			if img.src.loaded && img.err == nil {
 				img.ResizeForPageSize(width, height)
 			}
 		}
-	})
+	}); err != nil {
+		panic(err)
+	}
 }
 
 func (self *ImageCollection) DeleteAllVisiblePlacements(lp *loop.Loop) {
@@ -294,7 +296,7 @@ func (self *ImageCollection) LoadAll() {
 	defer self.mutex.Unlock()
 	ctx := images.Context{}
 	all := utils.Values(self.images)
-	ctx.Parallel(0, len(self.images), func(nums <-chan int) {
+	if err := ctx.SafeParallel(0, len(self.images), func(nums <-chan int) {
 		for i := range nums {
 			img := all[i]
 			if !img.src.loaded {
@@ -305,7 +307,9 @@ func (self *ImageCollection) LoadAll() {
 				img.src.loaded = true
 			}
 		}
-	})
+	}); err != nil {
+		panic(err)
+	}
 }
 
 func NewImageCollection(paths ...string) *ImageCollection {

tools/tui/loop/read.go

@@ -44,6 +44,12 @@ func read_ignoring_temporary_errors(f *tty.Term, buf []byte) (int, error) {
 }
 
 func read_from_tty(pipe_r *os.File, term *tty.Term, results_channel chan<- []byte, err_channel chan<- error, quit_channel <-chan byte, leftover_channel chan<- []byte) {
+	defer func() {
+		if r := recover(); r != nil {
+			text, _ := utils.Format_stacktrace_on_panic(r)
+			err_channel <- fmt.Errorf("%s", text)
+		}
+	}()
 	keep_going := true
 	pipe_fd := int(pipe_r.Fd())
 	tty_fd := term.Fd()
@@ -115,6 +121,12 @@ func read_until_primary_device_attributes_response(term *tty.Term, initial_bytes
 	}
 	received := make(chan error)
 	go func() {
+		defer func() {
+			if r := recover(); r != nil {
+				text, _ := utils.Format_stacktrace_on_panic(r)
+				received <- fmt.Errorf("%s", text)
+			}
+		}()
 		buf := make([]byte, 1024)
 		n, err := read_ignoring_temporary_errors(term, buf)
 		if n > 0 {

tools/tui/loop/write.go

@@ -168,6 +168,12 @@ func write_to_tty(
 	pipe_r *os.File, term *tty.Term,
 	job_channel <-chan write_msg, err_channel chan<- error, write_done_channel chan<- IdType,
 ) {
+	defer func() {
+		if r := recover(); r != nil {
+			text, _ := utils.Format_stacktrace_on_panic(r)
+			err_channel <- fmt.Errorf("%s", text)
+		}
+	}()
 	keep_going := true
 	defer func() {
 		pipe_r.Close()

tools/unicode_names/query.go

@@ -110,11 +110,13 @@ func marks_for_query(query string) (ans mark_set) {
 	prefixes := strings.Split(strings.ToLower(query), " ")
 	results := make(chan mark_set, len(prefixes))
 	ctx := images.Context{}
-	ctx.Parallel(0, len(prefixes), func(nums <-chan int) {
+	if err := ctx.SafeParallel(0, len(prefixes), func(nums <-chan int) {
 		for i := range nums {
 			results <- find_matching_codepoints(prefixes[i])
 		}
-	})
+	}); err != nil {
+		panic(err)
+	}
 	close(results)
 	for x := range results {
 		if ans == nil {

tools/utils/images/to_rgba.go

@@ -321,7 +321,7 @@ func (self *Context) run_paste(src Scanner, background image.Image, pos image.Po
 	default:
 		panic(fmt.Sprintf("Unsupported image type: %v", v))
 	}
-	self.Parallel(interRect.Min.Y, interRect.Max.Y, func(ys <-chan int) {
+	if err := self.SafeParallel(interRect.Min.Y, interRect.Max.Y, func(ys <-chan int) {
 		for y := range ys {
 			x1 := interRect.Min.X - pasteRect.Min.X
 			x2 := interRect.Max.X - pasteRect.Min.X
@@ -333,7 +333,9 @@ func (self *Context) run_paste(src Scanner, background image.Image, pos image.Po
 			src.scan(x1, y1, x2, y2, dst)
 			postprocess(dst)
 		}
-	})
+	}); err != nil {
+		panic(err)
+	}
 
 }
 

tools/utils/images/transforms.go

@@ -27,18 +27,20 @@ func reverse_row(bytes_per_pixel int, pix []uint8) {
 
 func (self *Context) FlipPixelsH(bytes_per_pixel, width, height int, pix []uint8) {
 	stride := bytes_per_pixel * width
-	self.Parallel(0, height, func(ys <-chan int) {
+	if err := self.SafeParallel(0, height, func(ys <-chan int) {
 		for y := range ys {
 			i := y * stride
 			reverse_row(bytes_per_pixel, pix[i:i+stride])
 		}
-	})
+	}); err != nil {
+		panic(err)
+	}
 }
 
 func (self *Context) FlipPixelsV(bytes_per_pixel, width, height int, pix []uint8) {
 	stride := bytes_per_pixel * width
 	num := height / 2
-	self.Parallel(0, num, func(ys <-chan int) {
+	if err := self.SafeParallel(0, num, func(ys <-chan int) {
 		for y := range ys {
 			upper := y
 			lower := height - 1 - y
@@ -50,6 +52,7 @@ func (self *Context) FlipPixelsV(bytes_per_pixel, width, height int, pix []uint8
 				as[i], bs[i] = bs[i], as[i]
 			}
 		}
-	})
-
+	}); err != nil {
+		panic(err)
+	}
 }

tools/utils/images/utils.go

@@ -7,6 +7,8 @@ import (
 	"runtime"
 	"sync"
 	"sync/atomic"
+
+	"github.com/kovidgoyal/kitty/tools/utils"
 )
 
 var _ = fmt.Print
@@ -31,8 +33,10 @@ func (self *Context) EffectiveNumberOfThreads() int {
 	return ans
 }
 
-// parallel processes the data in separate goroutines.
-func (self *Context) Parallel(start, stop int, fn func(<-chan int)) {
+// parallel processes the data in separate goroutines. If any of them panics,
+// returns an error. Note that if multiple goroutines panic, only one error is
+// returned.
+func (self *Context) SafeParallel(start, stop int, fn func(<-chan int)) (err error) {
 	count := stop - start
 	if count < 1 {
 		return
@@ -49,9 +53,16 @@ func (self *Context) Parallel(start, stop int, fn func(<-chan int)) {
 	for range procs {
 		wg.Add(1)
 		go func() {
-			defer wg.Done()
+			defer func() {
+				if r := recover(); r != nil {
+					text, _ := utils.Format_stacktrace_on_panic(r)
+					err = fmt.Errorf("%s", text)
+				}
+				wg.Done()
+			}()
 			fn(c)
 		}()
 	}
 	wg.Wait()
+	return
 }