[gnome-builder] messages: Replace plain \n with full CRLF

[Christian Hergert <chergert src gnome org>]

commit 559f6455b2e39bbb2957a52ee55fc81b7a0c8831
Author: vanadiae <vanadiae35 gmail com>
Date:   Tue Feb 23 21:15:39 2021 +0100

    messages: Replace plain \n with full CRLF
    
    A VteTerminal expects newlines to be done with \r\n (CRLF), whereas
    most programs output \n on Unix OSes, so if errors are passed from
    called programs to the messages panel, then they'll appear strangely e.g
    abcdef
          ghijkl
                mnop
    instead of:
    abcdef
    ghijkl
    mnop

 src/plugins/messages/gbp-messages-panel.c | 48 +++++++++++++++++++++++++++++--
 1 file changed, 46 insertions(+), 2 deletions(-)
---
diff --git a/src/plugins/messages/gbp-messages-panel.c b/src/plugins/messages/gbp-messages-panel.c
index a17452f53..fb3438a3c 100644
--- a/src/plugins/messages/gbp-messages-panel.c
+++ b/src/plugins/messages/gbp-messages-panel.c
@@ -37,6 +37,44 @@ struct _GbpMessagesPanel
 
 G_DEFINE_TYPE (GbpMessagesPanel, gbp_messages_panel, DZL_TYPE_DOCK_WIDGET)
 
+static char *
+ensure_crlf (const char *in_s)
+{
+  GString *s = g_string_new (NULL);
+  const char *p = in_s;
+  const char *prev_p = in_s;
+
+  g_assert (in_s != NULL);
+
+  while ((p = strchr (p, '\n')) != NULL)
+    {
+      /* This is to avoid a segfault that would occur if trying to deref in_s - 1. */
+      if (p == in_s)
+        {
+          g_string_append (s, "\r\n");
+          ++p;
+        }
+      else
+        {
+          if (p[-1] == '\r')
+            {
+              ++p;
+              g_string_append_len (s, prev_p, (gssize)(p - prev_p));
+            }
+          else
+            {
+              g_string_append_len (s, prev_p, (gssize)(p - prev_p));
+              g_string_append (s, "\r\n");
+              ++p;
+            }
+        }
+
+      prev_p = p;
+    }
+
+  return g_string_free (s, FALSE);
+}
+
 static void
 gbp_messages_panel_log_cb (GbpMessagesPanel *self,
                            GLogLevelFlags    log_level,
@@ -44,11 +82,15 @@ gbp_messages_panel_log_cb (GbpMessagesPanel *self,
                            const gchar      *message,
                            IdeContext       *context)
 {
+  g_autofree char *out_message = NULL;
+
   g_assert (GBP_IS_MESSAGES_PANEL (self));
   g_assert (message != NULL);
   g_assert (IDE_IS_CONTEXT (context));
 
-  vte_terminal_feed (VTE_TERMINAL (self->terminal), message, -1);
+  out_message = ensure_crlf (message);
+
+  vte_terminal_feed (VTE_TERMINAL (self->terminal), out_message, -1);
   vte_terminal_feed (VTE_TERMINAL (self->terminal), "\r\n", 2);
   dzl_dock_item_needs_attention (DZL_DOCK_ITEM (&self->parent_instance));
   gtk_widget_show (GTK_WIDGET (self));
@@ -58,7 +100,7 @@ gbp_messages_panel_log_cb (GbpMessagesPanel *self,
 static gboolean
 do_log (gpointer data)
 {
-  ide_context_warning (data, "(some log message here)");
+  ide_context_warning (data, "(some log message here)\nfoo\nbaz");
   return G_SOURCE_CONTINUE;
 }
 #endif
@@ -77,6 +119,8 @@ gbp_messages_panel_set_context (GtkWidget  *widget,
 #if 0
   if (context != NULL)
     g_timeout_add (1000, do_log, context);
+
+  g_assert (g_strcmp0 (ensure_crlf ("\nfoo\r\nbar\nbaz\r\r\n"), "\r\nfoo\r\nbar\r\nbaz\r\r\n") == 0);
 #endif
 }