vsh: Don't init history in cmdComplete()

Recent rework of virshtest uncovered a subtle bug that was
dormant in now vsh but before that even in monolithic virsh.

In vsh.c there's this vshReadlineInit() function that's supposed
to initialize readline library, i.e. set those global rl_*
pointers.  But it also initializes history library. Then, when
virsh/virt-admin quits, vshReadlineDeinit() is called which
writes history into a file (ensuring the parent directory
exists). So far no problem.

Problem arises when cmdComplete() is called (from a bash
completer, for instance). It does not guard call to
vshReadlineInit() with check for interactive shell (and it should
not), but it sets ctl->historyfile which signals to
vshReadlineDeinit() the history should be written.

Now, no real history is written, because nothing was entered on
the stdin, but the parent directory is created nevertheless. With
recent movement in virshtest.c this means some test cases might
create virsh history file which breaks our promise of not
touching user's data in test suite.

Resolves: https://bugs.gentoo.org/931109
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>

diff --git a/tools/vsh.c b/tools/vsh.c
index 58855f63babea0aa832a467f00a8381d0fd5bb3e..e74045c24eba9c6a80d5946355f188c2f1556923 100644 (file)
--- a/tools/vsh.c
+++ b/tools/vsh.c
@@ -2973,7 +2973,7 @@ vshReadlineInit(vshControl *ctl)
     const char *quote_characters = "\"'";
 
     /* initialize readline stuff only once */
-    if (ctl->historydir)
+    if (autoCompleteOpaque)
         return 0;
 
     /* Opaque data for autocomplete callbacks. */
@@ -2989,6 +2989,11 @@ vshReadlineInit(vshControl *ctl)
     rl_completer_quote_characters = quote_characters;
     rl_char_is_quoted_p = vshReadlineCharIsQuoted;
 
+    /* Stuff below is needed only for interactive mode. */
+    if (!ctl->imode) {
+        return 0;
+    }
+
     histsize_env = g_strdup_printf("%s_HISTSIZE", ctl->env_prefix);
 
     /* Limit the total size of the history buffer */
@@ -3149,7 +3154,7 @@ vshInit(vshControl *ctl, const vshCmdGrp *groups)
     cmdGroups = groups;
 
     if (vshInitDebug(ctl) < 0 ||
-        (ctl->imode && vshReadlineInit(ctl) < 0))
+        vshReadlineInit(ctl) < 0)
         return false;
 
     return true;
@@ -3168,7 +3173,7 @@ vshInitReload(vshControl *ctl)
 
     if (ctl->imode)
         vshReadlineDeinit(ctl);
-    if (ctl->imode && vshReadlineInit(ctl) < 0)
+    if (vshReadlineInit(ctl) < 0)
         return false;
 
     return true;