Fix/mute issues found by Coverity scan

This makes the code free of Coverity scan issues.
It is sometimes quite pedantic and expects/suggests some
coding habits, thus certain changes may look weird, but for a good
thing, I hope. The code is also tagged with Coverity scan
suppressions, to keep the code as is and hide the warning too.
Also note that Coverity treats g_return_if_fail(), g_assert() and
similar macros as unreliable, and it's true these can be disabled
during the compile time, thus it brings in other set of 'weird'
changes.

4 files changed, 12 insertions, 9 deletions

diff --git a/libemail-engine/e-mail-session.c b/libemail-engine/e-mail-session.c
index 38eae7791d..23ed2ce4de 100644
--- a/libemail-engine/e-mail-session.c
+++ b/libemail-engine/e-mail-session.c
@@ -190,7 +190,7 @@ user_message_response_cb (GObject *source,
 	}
 
 	/* waiting for a response? */
-	if (m && m->button_captions)
+	if (m->button_captions)
 		e_flag_set (m->done);
 
 	/* check for pendings */
diff --git a/libemail-engine/e-mail-utils.c b/libemail-engine/e-mail-utils.c
index d4bb9b5050..9610da7419 100644
--- a/libemail-engine/e-mail-utils.c
+++ b/libemail-engine/e-mail-utils.c
@@ -86,8 +86,6 @@ em_utils_folder_is_drafts (ESourceRegistry *registry,
 
 	folder_uri = e_mail_folder_uri_from_folder (folder);
 
-	store = camel_folder_get_parent_store (folder);
-
 	extension_name = E_SOURCE_EXTENSION_MAIL_COMPOSITION;
 	list = e_source_registry_list_sources (registry, extension_name);
 
@@ -157,8 +155,6 @@ em_utils_folder_is_templates (ESourceRegistry *registry,
 
 	folder_uri = e_mail_folder_uri_from_folder (folder);
 
-	store = camel_folder_get_parent_store (folder);
-
 	extension_name = E_SOURCE_EXTENSION_MAIL_COMPOSITION;
 	list = e_source_registry_list_sources (registry, extension_name);
 
@@ -227,8 +223,6 @@ em_utils_folder_is_sent (ESourceRegistry *registry,
 
 	folder_uri = e_mail_folder_uri_from_folder (folder);
 
-	store = camel_folder_get_parent_store (folder);
-
 	extension_name = E_SOURCE_EXTENSION_MAIL_SUBMISSION;
 	list = e_source_registry_list_sources (registry, extension_name);
 
diff --git a/libemail-engine/mail-folder-cache.c b/libemail-engine/mail-folder-cache.c
index e54cdbb09c..672447c57e 100644
--- a/libemail-engine/mail-folder-cache.c
+++ b/libemail-engine/mail-folder-cache.c
@@ -32,6 +32,7 @@
 #include <config.h>
 #endif
 
+#include <errno.h>
 #include <string.h>
 #include <time.h>
 
@@ -1152,12 +1153,18 @@ rename_folders (MailFolderCache *cache,
 	e_filename_make_safe (newuri);
 	oldfile = g_strdup_printf ("%s/custom_view-%s.xml", config_dir, olduri);
 	newfile = g_strdup_printf ("%s/custom_view-%s.xml", config_dir, newuri);
-	g_rename (oldfile, newfile);
+	if (g_rename (oldfile, newfile) == -1) {
+		g_warning ("%s: Failed to rename '%s' to '%s': %s", G_STRFUNC,
+			   oldfile, newfile, g_strerror (errno));
+	}
 	g_free (oldfile);
 	g_free (newfile);
 	oldfile = g_strdup_printf ("%s/current_view-%s.xml", config_dir, olduri);
 	newfile = g_strdup_printf ("%s/current_view-%s.xml", config_dir, newuri);
-	g_rename (oldfile, newfile);
+	if (g_rename (oldfile, newfile) == -1) {
+		g_warning ("%s: Failed to rename '%s' to '%s': %s", G_STRFUNC,
+			   oldfile, newfile, g_strerror (errno));
+	}
 	g_free (oldfile);
 	g_free (newfile);
 	g_free (olduri);
diff --git a/libemail-engine/mail-mt.c b/libemail-engine/mail-mt.c
index 19ed41b0dc..96f8e7267f 100644
--- a/libemail-engine/mail-mt.c
+++ b/libemail-engine/mail-mt.c
@@ -655,6 +655,8 @@ mail_call_main (mail_call_t type,
 	ret = m->ret;
 	mail_msg_unref (m);
 
+	/* the m->ap is freed on the message end, at do_free() above */
+	/* coverity[missing_va_end] */
 	return ret;
 }