trans.c : reworking of transaction interruptions

My two previous hacks related to this part
(8038190c7c4786e1c49494eea1b40cdddcbd5136 and
b15a5194d1a8485a2769560e49e6ff03e1862533) were caused by the lack of
understanding of a feature introduced a while ago:
Better control over CTRL-C interruptions -- do not leave the DB in an
inconsistent state (54008798efcc9646f622f6b052ecd83281d57cda).

Now I have been looking at this commit, and the added feature is indeed
interesting. The main problem I had with it is that it does a rather
unusual use of alpm_trans_release, which caused a few problems that I tried
to fix in a weird way. I think these problems were caused by the fact that
there weren't any difference between "interrupt transaction" and "release a
transaction which failed" actions from the alpm_trans_release POV.  So I
decided to add a new function instead, alpm_trans_interrupt, which is
called on Ctrl+C, and which only sets trans->state to STATE_INTERRUPTED so
that remove_commit and add_commit can exit cleanly at a safe moment. This
allowed me to revert my two previous hacks as well.

Also ensure we handle SIGINT correctly in all cases- if a transaction is
not ongoing, then we can free the transaction and exit quickly.

Signed-off-by: Chantry Xavier <shiningxc@gmail.com>
Signed-off-by: Dan McGee <dan@archlinux.org>

1 files changed, 8 insertions, 3 deletions

diff --git a/src/pacman/pacman.c b/src/pacman/pacman.c
index 2b748a1c..aa128261 100644
--- a/src/pacman/pacman.c
+++ b/src/pacman/pacman.c
@@ -207,9 +207,14 @@ static void cleanup(int signum)
 		pm_fprintf(stderr, PM_LOG_ERROR, "Internal pacman error: Segmentation fault.\n"
 		        "Please submit a full bug report with --debug if appropriate.\n");
 		exit(signum);
-	} else if((signum == SIGINT) && (alpm_trans_release() == -1)
-						&& (pm_errno == PM_ERR_TRANS_COMMITING)) {
-		return;
+	} else if((signum == SIGINT)) {
+		if(alpm_trans_interrupt() == 0) {
+			/* a transaction is being interrupted, don't exit pacman yet. */
+			return;
+		} else {
+			/* no commiting transaction, we can release it now and then exit pacman */
+			alpm_trans_release();
+		}
 	}
 
 	/* free alpm library resources */