Bug#451130: Patch suggestion

[Regis Boudin <regis@boudin.name>]

tag 451130 patch
thanks

Hi,

Keeping up with things, here is a relatively simple patch. If the
opening of a template or config database file fails with ENOENT, it
tries to open it for writing and close it. In case of success, it
returns the operation as having succeeded (no point trying reading any
data at that point, the file is empty anyway).

As usual, any comment or feedback to help getting the patch applied
would be more than welcome.

Regis

>From bae4706120f05b4ba528071490f86474a022b626 Mon Sep 17 00:00:00 2001
From: Regis Boudin <regis@boudin.name>
Date: Mon, 13 Jun 2011 21:47:42 +0100
Subject: [PATCH] Try to create the database files if they don't exist

---
 debian/changelog                   |    1 +
 src/modules/db/rfc822db/rfc822db.c |   40 +++++++++++++++++++++++++++---------
 2 files changed, 31 insertions(+), 10 deletions(-)

diff --git a/debian/changelog b/debian/changelog
index 7d7300b..8338229 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -7,6 +7,7 @@ cdebconf (0.156) UNRELEASED; urgency=low
   * Fix FTBFS with the future GCC 4.6.1 (Closes: #625317).
   * Implement handling of multiple flags in the rfc822db backend. Fix some
     issue in it, thanks to Samuel Thibault (Closes: #628084).
+  * Try to create the database files if they don't exist. Closes: #451130.
 
   [ Samuel Thibault ]
   * Add -lpthread to fix loading on hurd the gtk backend which needs it.
diff --git a/src/modules/db/rfc822db/rfc822db.c b/src/modules/db/rfc822db/rfc822db.c
index fd7063b..0897679 100644
--- a/src/modules/db/rfc822db/rfc822db.c
+++ b/src/modules/db/rfc822db/rfc822db.c
@@ -163,6 +163,19 @@ static unsigned int parse_flags(char *string)
     return ret;
 }
 
+static int crate_database_file(const char *path)
+{
+    int retval = DC_NOTOK;
+    INFO(INFO_VERBOSE, "Database file doesn't exist. Trying to create it");
+    if (((outf = fopen(path, "w")) != NULL) && (fclose(outf) != EOF))
+        retval = DC_OK;
+    else
+        INFO(INFO_VERBOSE, "Cannot create database file %s: %s",
+             path, strerror(errno));
+    outf = NULL;
+    return retval;
+}
+
 void rfc822db_template_destroyitem(void *data)
 {
     template_deref((struct template *) data);
@@ -217,13 +230,18 @@ static int rfc822db_template_load(struct template_db *db)
     INFO(INFO_VERBOSE, "rfc822db_template_load(db)");
     snprintf(tmp, sizeof(tmp), "%s::path", db->configpath);
     path = db->config->get(db->config, tmp, 0);
-    if (path == NULL ||
-        (inf = fopen(path, "r")) == NULL)
+    if (path == NULL)
     {
-        INFO(INFO_VERBOSE, "Cannot open template file %s",
-            path ? path : "<empty>");
+        INFO(INFO_VERBOSE, "Cannot open template file. Path not set");
         return DC_NOTOK;
     }
+    else if ((inf = fopen(path, "r")) == NULL)
+    {
+        if (errno == ENOENT)
+            return crate_database_file(path);
+        else
+            return DC_NOTOK;
+    }
 
     while ((header = rfc822_parse_stanza(inf)) != NULL)
     {
@@ -573,15 +591,17 @@ static int rfc822db_question_load(struct question_db *db)
     INFO(INFO_VERBOSE, "rfc822db_question_load(db)");
     snprintf(tmp, sizeof(tmp), "%s::path", db->configpath);
     path = db->config->get(db->config, tmp, 0);
-    if (path == NULL ||
-        (inf = fopen(path, "r")) == NULL)
+    if (path == NULL)
+    {
+        INFO(INFO_VERBOSE, "Cannot open config database. Path not set");
+        return DC_NOTOK;
+    }
+    else if ((inf = fopen(path, "r")) == NULL)
     {
         if (errno == ENOENT)
+            return crate_database_file(path);
+        else
             return DC_NOTOK;
-
-        INFO(INFO_VERBOSE, "Cannot open config database %s: %s",
-            path ? path : "<empty>", strerror(errno));
-        return DC_NOTOK;
     }
 
     while ((header = rfc822_parse_stanza(inf)) != NULL)
-- 
1.7.6.rc1