Fix some of the problems reported by cppcheck

Thanks to Christian for running the static code analysis tool against
subsurface...

There were some false positives, a few style issues that I'll ignore for
now, and two actual potential bugs.

First: Don't check unsigned variables for < 0

This has been around for a while and we are lucky that while technically a
bug it still works as expected. Passing a negative idx simply turns it
into a very large unsigned integer which then fails the > dive_table.nr
test. So it still gets a NULL returned. A bug? Yes. Critical? No.

Mismatched allocation and free

This is an actual bug that potentially could cause issues. We allocate
memory with malloc and free it with g_free. Not good.

Reported-by: Cristian Ionescu-Idbohrn <cristian.ionescu-idbohrn@axis.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

5 files changed, 7 insertions, 7 deletions

diff --git a/dive.c b/dive.c
index 54784cdba..52ec64517 100644
--- a/dive.c
+++ b/dive.c
@@ -277,7 +277,7 @@ static void sanitize_gasmix(struct gasmix *mix)
 	/* Sane mix? */
 	if (o2 <= 1000 && he <= 1000 && o2+he <= 1000)
 		return;
-	fprintf(stderr, "Odd gasmix: %d O2 %d He\n", o2, he);
+	fprintf(stderr, "Odd gasmix: %u O2 %u He\n", o2, he);
 	memset(mix, 0, sizeof(*mix));
 }
 
diff --git a/dive.h b/dive.h
index d756eba15..e443ce965 100644
--- a/dive.h
+++ b/dive.h
@@ -366,7 +366,7 @@ extern struct dive_table dive_table;
 extern int selected_dive;
 #define current_dive (get_dive(selected_dive))
 
-static inline struct dive *get_dive(unsigned int nr)
+static inline struct dive *get_dive(int nr)
 {
 	if (nr >= dive_table.nr || nr < 0)
 		return NULL;
diff --git a/divelist.c b/divelist.c
index 514fdfed1..f032e6243 100644
--- a/divelist.c
+++ b/divelist.c
@@ -110,7 +110,7 @@ void dump_selection(void)
 	int i;
 	struct dive *dive;
 
-	printf("currently selected are %d dives:", amount_selected);
+	printf("currently selected are %u dives:", amount_selected);
 	for_each_dive(i, dive) {
 		if (dive->selected)
 			printf(" %d", i);
diff --git a/equipment.c b/equipment.c
index adfb02989..fc31d9729 100644
--- a/equipment.c
+++ b/equipment.c
@@ -96,13 +96,13 @@ static void convert_volume_pressure(int ml, int mbar, double *v, double *p)
 			volume *= bar_to_atm(mbar / 1000.0);
 		}
 
-		if (output_units.pressure == PSI) {
+		if (output_units.pressure == PSI)
 			pressure = mbar_to_PSI(mbar);
-		} else
+		else
 			pressure = mbar / 1000.0;
+		*p = pressure;
 	}
 	*v = volume;
-	*p = pressure;
 }
 
 static int convert_weight(int grams, double *m)
diff --git a/gtk-gui.c b/gtk-gui.c
index d797b8d56..167517ebe 100644
--- a/gtk-gui.c
+++ b/gtk-gui.c
@@ -226,7 +226,7 @@ static gboolean ask_save_changes()
 			"You have unsaved changes to file: %s \nWould you like to save those before closing the datafile?",
 			existing_filename);
 		label = gtk_label_new (label_text);
-		g_free(label_text);
+		free(label_text);
 	}
 	gtk_container_add (GTK_CONTAINER (content), label);
 	gtk_widget_show_all (dialog);