Re: [PATCH] enable elaped time with incappendhistory

[Peter Stephenson <p.stephenson@xxxxxxxxxxx>]

On Thu, 10 Oct 2013 18:30:35 +0100
Peter Stephenson <p.stephenson@xxxxxxxxxxx> wrote:
> I think this change has broken use of "fc -p" to switch files
> temporarily within an zshaddhistory hook, too, but I'll have to look
> tomorrow.

Yes, it did.

I think, after trying it out and pondering the result, this sorts it all
out, but I've added a tortured essay anyway.

There is some kind of law of conservation of spaghetti code for zsh.

I'm wondering if there's a neater way of doing this, but I think the
answer is "not much neater, anyway".

diff --git a/Src/hist.c b/Src/hist.c
index bd650e8..5531f47 100644
--- a/Src/hist.c
+++ b/Src/hist.c
@@ -937,12 +937,21 @@ hbegin(int dohist)
     /*
      * For INCAPPENDHISTORY, when interactive, save the history here
      * as it gives a better estimate of the times of commands.
+     *
      * If SHAREHISTORY is also set continue to do so in the
      * standard place, because that's safer about reading and
      * rewriting history atomically.
+     *
+     * The histsave_stack_pos test won't usually fail here.
+     * We need to test the opposite for the hend() case because we
+     * need to save in the history file we've switched to, but then
+     * we pop immediately after that so the variable becomes zero.
+     * We will already have saved the line and restored the history
+     * so that (correctly) nothing happens here.  But it shows
+     * I thought about it.
      */
     if (isset(INCAPPENDHISTORY) && !isset(SHAREHISTORY) &&
-	!(histactive & HA_NOINC) && !strin)
+	!(histactive & HA_NOINC) && !strin && histsave_stack_pos == 0)
 	savehistfile(hf, 0, HFILE_USE_OPTIONS | HFILE_FAST);
 }
 
@@ -1348,7 +1357,11 @@ hend(Eprog prog)
     chline = hptr = NULL;
     chwords = NULL;
     histactive = 0;
-    if (isset(SHAREHISTORY) && histfileIsLocked())
+    /*
+     * For normal INCAPPENDHISTORY case and reasoning, see hbegin().
+     */
+    if (isset(SHAREHISTORY) ? histfileIsLocked() :
+	(isset(INCAPPENDHISTORY) && histsave_stack_pos != 0))
 	savehistfile(hf, 0, HFILE_USE_OPTIONS | HFILE_FAST);
     unlockhistfile(hf); /* It's OK to call this even if we aren't locked */
     /*

-- 
Peter Stephenson <p.stephenson@xxxxxxxxxxx>       Principal Software Engineer
Tel: +44 (0)1223 434724              Samsung Cambridge Solution Centre
St John's House, St John's Innovation Park,
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