qemu-img: Factor out accumulate_options() helper

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200415074927.19897-8-armbru@redhat.com>
diff --git a/qemu-img.c b/qemu-img.c
index 821cbf6..d36b21b 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -223,6 +223,25 @@
     return true;
 }
 
+static int accumulate_options(char **options, char *optarg)
+{
+    char *new_options;
+
+    if (!is_valid_option_list(optarg)) {
+        error_report("Invalid option list: %s", optarg);
+        return -1;
+    }
+
+    if (!*options) {
+        *options = g_strdup(optarg);
+    } else {
+        new_options = g_strdup_printf("%s,%s", *options, optarg);
+        g_free(*options);
+        *options = new_options;
+    }
+    return 0;
+}
+
 static QemuOptsList qemu_source_opts = {
     .name = "source",
     .implied_opt_name = "file",
@@ -482,17 +501,9 @@
             fmt = optarg;
             break;
         case 'o':
-            if (!is_valid_option_list(optarg)) {
-                error_report("Invalid option list: %s", optarg);
+            if (accumulate_options(&options, optarg) < 0) {
                 goto fail;
             }
-            if (!options) {
-                options = g_strdup(optarg);
-            } else {
-                char *old_options = options;
-                options = g_strdup_printf("%s,%s", options, optarg);
-                g_free(old_options);
-            }
             break;
         case 'q':
             quiet = true;
@@ -2127,17 +2138,9 @@
             s.compressed = true;
             break;
         case 'o':
-            if (!is_valid_option_list(optarg)) {
-                error_report("Invalid option list: %s", optarg);
+            if (accumulate_options(&options, optarg) < 0) {
                 goto fail_getopt;
             }
-            if (!options) {
-                options = g_strdup(optarg);
-            } else {
-                char *old_options = options;
-                options = g_strdup_printf("%s,%s", options, optarg);
-                g_free(old_options);
-            }
             break;
         case 'l':
             if (strstart(optarg, SNAPSHOT_OPT_BASE, NULL)) {
@@ -3953,18 +3956,10 @@
             help();
             break;
         case 'o':
-            if (!is_valid_option_list(optarg)) {
-                error_report("Invalid option list: %s", optarg);
+            if (accumulate_options(&options, optarg) < 0) {
                 ret = -1;
                 goto out_no_progress;
             }
-            if (!options) {
-                options = g_strdup(optarg);
-            } else {
-                char *old_options = options;
-                options = g_strdup_printf("%s,%s", options, optarg);
-                g_free(old_options);
-            }
             break;
         case 'f':
             fmt = optarg;
@@ -4855,17 +4850,9 @@
             out_fmt = optarg;
             break;
         case 'o':
-            if (!is_valid_option_list(optarg)) {
-                error_report("Invalid option list: %s", optarg);
+            if (accumulate_options(&options, optarg) < 0) {
                 goto out;
             }
-            if (!options) {
-                options = g_strdup(optarg);
-            } else {
-                char *old_options = options;
-                options = g_strdup_printf("%s,%s", options, optarg);
-                g_free(old_options);
-            }
             break;
         case 'l':
             if (strstart(optarg, SNAPSHOT_OPT_BASE, NULL)) {