Re: Segfault in hrealloc somewhere between rpromts and syntax highlighting

[Bart Schaefer <schaefer@brasslantern.com>]

On Apr 13,  2:29am, Jun T. wrote:
} Subject: Re: Segfault in hrealloc somewhere between rpromts and syntax hig
}
} 2014/04/06 16:05, Bart Schaefer <schaefer@brasslantern.com> wrote:
} > diff --git a/Src/Zle/zle_tricky.c b/Src/Zle/zle_tricky.c
} > index 3c7cff9..b916bd6 100644
} > (snip)
} > 	if (strcmp(zlemetaline, ol)) {
} > +	    zle_restore_positions();
} 
} It seems this causes the following problem:
} 
} $ echo foobar<RET>
} $ echo !$<TAB>
} $ echo fo
} 
} Maybe zlemetacs/zlematall need not to be restored?

Hmm, I think it's more complicated than that.  Assuming that the various
positions have been correctly updated when expansion changed the buffer,
then we don't want to restore *anything*, we just want to discard the
most recent saved state.

I'm not sure how that affects the state of any previous call to
zle_save_positions(), but I have to assume that if it's possible for
the stack to be more than one element deep here, then whoever else is
calling zle_store_positions() is planning to do a complete unwind of
whatever doexpandhist() may have done.

On the other hand, compresult.c simply makes sure that restoring the
positions doesn't affect zlemetall, so perhaps this is too much.


diff --git a/Src/Zle/zle_tricky.c b/Src/Zle/zle_tricky.c
index b916bd6..499c4ae 100644
--- a/Src/Zle/zle_tricky.c
+++ b/Src/Zle/zle_tricky.c
@@ -2795,7 +2795,7 @@ doexpandhist(void)
     if (!err) {
 	zlemetacs = excs;
 	if (strcmp(zlemetaline, ol)) {
-	    zle_restore_positions();
+	    zle_free_positions();
 	    unmetafy_line();
 	    /* For vi mode -- reset the beginning-of-insertion pointer   *
 	     * to the beginning of the line.  This seems a little silly, *
diff --git a/Src/Zle/zle_utils.c b/Src/Zle/zle_utils.c
index 9cfa881..1089e27 100644
--- a/Src/Zle/zle_utils.c
+++ b/Src/Zle/zle_utils.c
@@ -710,6 +710,27 @@ zle_restore_positions(void)
 }
 
 /*
+ * Discard positions previously saved, the line has been updated.
+ */
+
+/**/
+mod_export void
+zle_free_positions(void)
+{
+    struct zle_position *oldpos = zle_positions;
+    struct zle_region *oldrhp;
+
+    zle_positions = oldpos->next;
+    oldrhp = oldpos->regions;
+    while (oldrhp) {
+	struct zle_region *nextrhp = oldrhp->next;
+	zfree(oldrhp, sizeof(*oldrhp));
+	oldrhp = nextrhp;
+    }
+    zfree(oldpos, sizeof(*oldpos));
+}
+
+/*
  * Basic utility functions for adding to line or removing from line.
  * At this level the counts supplied are raw character counts, so
  * the calling code must be aware of combining characters where