Re: zle: vi mode: wrong undo handling on fresh lines

["Jun T." <takimoto-j@xxxxxxxxxxxxxxxxx>]

Unconditionally calling vimergeundo() from docomplete() makes the
behavior of 'undo' in emacs mode. For example,

$ ls f<tab>
$ ls foo         # assume there is a file 'foo'
$ ls foo<undo>
$ ls f<undo>

now <undo> will remove the entire command line (the original behavior
is to remove only 'f').

If this is a problem, then consider the following patch
(this patch assume my patch in 32324 has been already applied):


diff --git a/Src/Zle/zle_main.c b/Src/Zle/zle_main.c
index 72650a8..316115a 100644
--- a/Src/Zle/zle_main.c
+++ b/Src/Zle/zle_main.c
@@ -1189,7 +1189,7 @@ zleread(char **lp, char **rp, int flags, int context, char *init, char *finish)
     zlereadflags = flags;
     zlecontext = context;
     histline = curhist;
-    vistartchange = 0;
+    vistartchange = -1;
     zleline = (ZLE_STRING_T)zalloc(((linesz = 256) + 2) * ZLE_CHAR_SIZE);
     *zleline = ZWC('\0');
     virangeflag = lastcmd = done = zlecs = zlell = mark = 0;
diff --git a/Src/Zle/zle_tricky.c b/Src/Zle/zle_tricky.c
index 49dae8a..99cdb8f 100644
--- a/Src/Zle/zle_tricky.c
+++ b/Src/Zle/zle_tricky.c
@@ -674,8 +674,11 @@ docomplete(int lst)
     if (viinsbegin > ztrsub(zlemetaline + wb, zlemetaline))
 	viinsbegin = ztrsub(zlemetaline + wb, zlemetaline);
     /* finish the current undo block and start a new one */
-    vimergeundo();
-    vistartchange = (curchange && curchange->prev) ? curchange->prev->changeno : 0;
+    if (vistartchange >= 0) {
+	vimergeundo();
+	vistartchange = (curchange && curchange->prev) ?
+			    curchange->prev->changeno : 0;
+    }
     /* If we added chline to the line buffer, reset the original contents. */
     if (ol) {
 	zlemetacs -= chl;
diff --git a/Src/Zle/zle_vi.c b/Src/Zle/zle_vi.c
index e6c10a1..64bdbd8 100644
--- a/Src/Zle/zle_vi.c
+++ b/Src/Zle/zle_vi.c
@@ -116,6 +116,8 @@ void
 vimergeundo(void)
 {
     struct change *current = curchange->prev;
+    if (vistartchange < 0)
+	return;
     while (current && current->changeno > vistartchange+1) {
 	current->flags |= CH_PREV;
 	current = current->prev;