3 files changed, 41 insertions, 8 deletions

diff --git a/util/error.c b/util/error.c
index 80c89a2079..57303fd05c 100644
--- a/util/error.c
+++ b/util/error.c
@@ -122,6 +122,29 @@ void error_setg_file_open_internal(Error **errp,
                               "Could not open '%s'", filename);
 }
 
+void error_vprepend(Error **errp, const char *fmt, va_list ap)
+{
+    GString *newmsg;
+
+    if (!errp) {
+        return;
+    }
+
+    newmsg = g_string_new(NULL);
+    g_string_vprintf(newmsg, fmt, ap);
+    g_string_append(newmsg, (*errp)->msg);
+    (*errp)->msg = g_string_free(newmsg, 0);
+}
+
+void error_prepend(Error **errp, const char *fmt, ...)
+{
+    va_list ap;
+
+    va_start(ap, fmt);
+    error_vprepend(errp, fmt, ap);
+    va_end(ap);
+}
+
 void error_append_hint(Error **errp, const char *fmt, ...)
 {
     va_list ap;
@@ -132,7 +155,7 @@ void error_append_hint(Error **errp, const char *fmt, ...)
         return;
     }
     err = *errp;
-    assert(err && errp != &error_abort);
+    assert(err && errp != &error_abort && errp != &error_fatal);
 
     if (!err->hint) {
         err->hint = g_string_new(NULL);
@@ -204,11 +227,21 @@ void error_report_err(Error *err)
 {
     error_report("%s", error_get_pretty(err));
     if (err->hint) {
-        error_printf_unless_qmp("%s\n", err->hint->str);
+        error_printf_unless_qmp("%s", err->hint->str);
     }
     error_free(err);
 }
 
+void error_reportf_err(Error *err, const char *fmt, ...)
+{
+    va_list ap;
+
+    va_start(ap, fmt);
+    error_vprepend(&err, fmt, ap);
+    va_end(ap);
+    error_report_err(err);
+}
+
 void error_free(Error *err)
 {
     if (err) {
diff --git a/util/qemu-error.c b/util/qemu-error.c
index c1574bb348..ecf5708478 100644
--- a/util/qemu-error.c
+++ b/util/qemu-error.c
@@ -200,8 +200,8 @@ static void error_print_loc(void)
 bool enable_timestamp_msg;
 /*
  * Print an error message to current monitor if we have one, else to stderr.
- * Format arguments like vsprintf().  The result should not contain
- * newlines.
+ * Format arguments like vsprintf().  The resulting message should be
+ * a single phrase, with no newline or trailing punctuation.
  * Prepend the current location and append a newline.
  * It's wrong to call this in a QMP monitor.  Use error_setg() there.
  */
@@ -224,8 +224,8 @@ void error_vreport(const char *fmt, va_list ap)
 
 /*
  * Print an error message to current monitor if we have one, else to stderr.
- * Format arguments like sprintf().  The result should not contain
- * newlines.
+ * Format arguments like sprintf().  The resulting message should be a
+ * single phrase, with no newline or trailing punctuation.
  * Prepend the current location and append a newline.
  * It's wrong to call this in a QMP monitor.  Use error_setg() there.
  */
diff --git a/util/qemu-option.c b/util/qemu-option.c
index a50eceae4a..a2d593ad2b 100644
--- a/util/qemu-option.c
+++ b/util/qemu-option.c
@@ -206,7 +206,7 @@ void parse_option_size(const char *name, const char *value,
         default:
             error_setg(errp, QERR_INVALID_PARAMETER_VALUE, name, "a size");
             error_append_hint(errp, "You may use k, M, G or T suffixes for "
-                    "kilobytes, megabytes, gigabytes and terabytes.");
+                    "kilobytes, megabytes, gigabytes and terabytes.\n");
             return;
         }
     } else {
@@ -647,7 +647,7 @@ QemuOpts *qemu_opts_create(QemuOptsList *list, const char *id,
             error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "id",
                        "an identifier");
             error_append_hint(errp, "Identifiers consist of letters, digits, "
-                              "'-', '.', '_', starting with a letter.");
+                              "'-', '.', '_', starting with a letter.\n");
             return NULL;
         }
         opts = qemu_opts_find(list, id);