core: fix color when the delimiter is not followed by a background color (closes #1867)

ChangeLog.adoc

@@ -40,6 +40,7 @@ New features::
 
 Bug fixes::
 
+  * core: fix color when the delimiter is not followed by a background color (issue #1867)
   * core: display chars the same way in chat and bars, replace tabulations by spaces in bars, display chars < 32 with letter in chat, do not display soft hyphens, zero width spaces and all non-printable chars (issue #1659, issue #1669, issue #1770)
   * core: fix context info in buffers with free content (issue #1832)
   * core: keep terminal title unchanged when option weechat.look.window_title is set to empty value (issue #1835, issue #1836)

src/gui/gui-color.c

@@ -424,7 +424,7 @@ gui_color_get_custom (const char *color_name)
             else
                 str_fg = string_strndup (ptr_color_name,
                                          pos_delim - ptr_color_name);
-            pos_bg = pos_delim + 1;
+            pos_bg = (pos_delim[1]) ? pos_delim + 1 : NULL;
         }
         else
         {

tests/unit/gui/test-gui-color.cpp

@@ -192,6 +192,10 @@ TEST(GuiColor, GetCustom)
               GUI_COLOR_BAR_BG_CHAR);
     STRCMP_EQUAL(string, gui_color_get_custom ("bar_bg"));
 
+    /* only delimiter (no-op) */
+    STRCMP_EQUAL("", gui_color_get_custom (","));
+    STRCMP_EQUAL("", gui_color_get_custom (":"));
+
     /* fg color */
     snprintf (string, sizeof (string),
               "%c%c09",
@@ -199,6 +203,14 @@ TEST(GuiColor, GetCustom)
               GUI_COLOR_FG_CHAR);
     STRCMP_EQUAL(string, gui_color_get_custom ("blue"));
 
+    /* fg color, delimiter and no bg color */
+    snprintf (string, sizeof (string),
+              "%c%c09",
+              GUI_COLOR_COLOR_CHAR,
+              GUI_COLOR_FG_CHAR);
+    STRCMP_EQUAL(string, gui_color_get_custom ("blue,"));
+    STRCMP_EQUAL(string, gui_color_get_custom ("blue:"));
+
     /* bg color */
     snprintf (string, sizeof (string),
               "%c%c09",