From 59df2adc071e0186ccd0ba7ea9387142e168d735 Mon Sep 17 00:00:00 2001 From: Aaron Lehmann Date: Mon, 7 Dec 2015 17:01:47 -0800 Subject: [PATCH] Fix the scoping of "diff" so its value doesn't leak between loop iterations In the existing code, "diff" has function scope and the value from the previous iteration may be used if it is not reset. This appears to be an oversight. This commit changes its scope to the for loop body. One confusing point is that the cursor movement escape sequences appear to be necessary even if the requested movement is 0. I haven't been able to figure out why this makes a difference. Signed-off-by: Aaron Lehmann --- pkg/jsonmessage/jsonmessage.go | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/pkg/jsonmessage/jsonmessage.go b/pkg/jsonmessage/jsonmessage.go index 4f7a6fafc0..f503b109f2 100644 --- a/pkg/jsonmessage/jsonmessage.go +++ b/pkg/jsonmessage/jsonmessage.go @@ -150,11 +150,11 @@ func (jm *JSONMessage) Display(out io.Writer, isTerminal bool) error { // each line and move the cursor while displaying. func DisplayJSONMessagesStream(in io.Reader, out io.Writer, terminalFd uintptr, isTerminal bool) error { var ( - dec = json.NewDecoder(in) - ids = make(map[string]int) - diff = 0 + dec = json.NewDecoder(in) + ids = make(map[string]int) ) for { + diff := 0 var jm JSONMessage if err := dec.Decode(&jm); err != nil { if err == io.EOF { @@ -180,11 +180,12 @@ func DisplayJSONMessagesStream(in io.Reader, out io.Writer, terminalFd uintptr, if isTerminal { fmt.Fprintf(out, "\n") } - diff = 0 } else { diff = len(ids) - line } if jm.ID != "" && isTerminal { + // NOTE: this appears to be necessary even if + // diff == 0. // [{diff}A = move cursor up diff rows fmt.Fprintf(out, "%c[%dA", 27, diff) } @@ -198,6 +199,8 @@ func DisplayJSONMessagesStream(in io.Reader, out io.Writer, terminalFd uintptr, } err := jm.Display(out, isTerminal) if jm.ID != "" && isTerminal { + // NOTE: this appears to be necessary even if + // diff == 0. // [{diff}B = move cursor down diff rows fmt.Fprintf(out, "%c[%dB", 27, diff) }