Description: Fix a number of error handling issues
Author: Stephen Kitt <skitt@debian.org>

* Avoid crashing when handling animation load errors.
* Correctly free current_filename in explorer-animation.
* Clarify if statements which were confusing the compiler's
  diagnostics in histogram-imager.

--- a/src/animation.c
+++ b/src/animation.c
@@ -376,19 +376,24 @@
     }
 }
 
-void animation_load_file(Animation *self, const gchar *filename) {
+gboolean animation_load_file(Animation *self, const gchar *filename) {
     FILE *f;
     AnimChunkState state;
 
-    g_return_if_fail((f = fopen(filename, "rb")));
-    g_return_if_fail(chunked_file_read_signature(f, FILE_SIGNATURE) ||
-		     chunked_file_read_signature(f, OLD_FILE_SIGNATURE));
+    if (!(f = fopen(filename, "rb"))) {
+	return FALSE;
+    }
+    if (!(chunked_file_read_signature(f, FILE_SIGNATURE) ||
+	  chunked_file_read_signature(f, OLD_FILE_SIGNATURE))) {
+	return FALSE;
+    }
 
     animation_clear(self);
     state.self = self;
     chunked_file_read_all(f, CHUNK_CALLBACK(animation_store_chunk), &state);
 
     fclose(f);
+    return TRUE;
 }
 
 void animation_save_file(Animation *self, const gchar *filename) {
--- a/src/main.c
+++ b/src/main.c
@@ -134,10 +134,14 @@
 	{
 	    GtkTreeIter iter;
 
-	    animation_load_file(animation, optarg);
-	    animate = TRUE;
-	    gtk_tree_model_get_iter_first(GTK_TREE_MODEL(animation->model), &iter);
-	    animation_keyframe_load(animation, &iter, PARAMETER_HOLDER(map));
+	    if (animation_load_file(animation, optarg)) {
+		animate = TRUE;
+		gtk_tree_model_get_iter_first(GTK_TREE_MODEL(animation->model), &iter);
+		animation_keyframe_load(animation, &iter, PARAMETER_HOLDER(map));
+	    } else {
+		fprintf(stderr, "Unable to load animation from %s\n", optarg);
+		return 1;
+	    }
 	    break;
 	}
 
@@ -210,7 +214,10 @@
 	    break;
 
 	case 1002: /* --chdir */
-	    chdir(optarg);
+	    if (!chdir(optarg)) {
+		perror("Error changing directory");
+		return 1;
+	    }
 	    break;
 
 	case 1003: /* --pidfile */
@@ -241,10 +248,14 @@
 	    } else if (g_strcasecmp(ext, ".fa") == 0) {
 	        GtkTreeIter iter;
 
-		animation_load_file(animation, argv[optind]);
-		animate = TRUE;
-	        gtk_tree_model_get_iter_first(GTK_TREE_MODEL(animation->model), &iter);
-	        animation_keyframe_load(animation, &iter, PARAMETER_HOLDER(map));
+		if (animation_load_file(animation, argv[optind])) {
+		    animate = TRUE;
+		    gtk_tree_model_get_iter_first(GTK_TREE_MODEL(animation->model), &iter);
+		    animation_keyframe_load(animation, &iter, PARAMETER_HOLDER(map));
+		} else {
+		    fprintf(stderr, "Unable to load animation from %s\n", argv[optind]);
+		    return 1;
+		}
 	    } else {
 	        usage(argv);
 	        return 1;
--- a/src/animation.h
+++ b/src/animation.h
@@ -82,7 +82,7 @@
 void         animation_clear                 (Animation           *self);
 
 /* Persistence */
-void         animation_load_file             (Animation           *self,
+gboolean     animation_load_file             (Animation           *self,
 					      const gchar         *filename);
 void         animation_save_file             (Animation           *self,
 					      const gchar         *filename);
--- a/src/explorer-animation.c
+++ b/src/explorer-animation.c
@@ -551,8 +551,9 @@
 	filename = gtk_file_chooser_get_filename (GTK_FILE_CHOOSER (dialog));
 	animation_load_file (self->animation, filename);
 	explorer_update_animation_length (self);
-	if (current_filename);
+	if (current_filename) {
 	    g_free (current_filename);
+	}
 	current_filename = filename;
     }
 #else
--- a/src/histogram-imager.c
+++ b/src/histogram-imager.c
@@ -888,10 +888,14 @@
 	current.a = ((int)(self->bgalpha       * (1-luma) + self->fgalpha       * luma)) >> 8;
 
 	/* Always clamp color components */
-	if (current.r<0) current.r = 0;  if (current.r>255) current.r = 255;
-	if (current.g<0) current.g = 0;  if (current.g>255) current.g = 255;
-	if (current.b<0) current.b = 0;  if (current.b>255) current.b = 255;
-	if (current.a<0) current.a = 0;  if (current.a>255) current.a = 255;
+	if (current.r<0) current.r = 0;
+	if (current.r>255) current.r = 255;
+	if (current.g<0) current.g = 0;
+	if (current.g>255) current.g = 255;
+	if (current.b<0) current.b = 0;
+	if (current.b>255) current.b = 255;
+	if (current.a<0) current.a = 0;
+	if (current.a>255) current.a = 255;
 
 	/* Colors are always ARGB order in little endian */
 	self->color_table.table[count] = IMAGEFU_COLOR(current.a, current.r, current.g, current.b);