Minor tweaks of copying text properties when padding strings

* src/editfns.c (styled_format): Don't include padding on the left
in the properties at the beginning of the string.  (Bug#23897)

* test/src/editfns-tests.el (format-properties): Add tests for
faces when the string is padded on the left or on the right.

2 files changed, 27 insertions, 3 deletions

diff --git a/src/editfns.c b/src/editfns.c
index 73f024409b1..4c8336b8c82 100644
--- a/src/editfns.c
+++ b/src/editfns.c
@@ -4175,13 +4175,13 @@ styled_format (ptrdiff_t nargs, Lisp_Object *args, bool message)
               convbytes += padding;
               if (convbytes <= buf + bufsize - p)
                 {
-                  info[n].start = nchars;
                   if (! minus_flag)
                     {
                       memset (p, ' ', padding);
                       p += padding;
                       nchars += padding;
                     }
+                  info[n].start = nchars;
 
                   if (p > buf
                       && multibyte
diff --git a/test/src/editfns-tests.el b/test/src/editfns-tests.el
index 62d7bc4f5be..507ceef2f7d 100644
--- a/test/src/editfns-tests.el
+++ b/test/src/editfns-tests.el
@@ -54,7 +54,7 @@
   ;; Bug #23859
   (should (ert-equal-including-properties
            (format "%4s" (propertize "hi" 'face 'bold))
-           #("  hi" 0 4 (face bold))))
+           #("  hi" 2 4 (face bold))))
 
   ;; Bug #23897
   (should (ert-equal-including-properties
@@ -64,4 +64,28 @@
            (format "%s" (concat (propertize "01" 'face 'bold)
                                 (propertize "23" 'face 'underline)
                                 "45"))
-           #("012345" 0 2 (face bold) 2 4 (face underline)))))
+           #("012345" 0 2 (face bold) 2 4 (face underline))))
+  ;; The last property range is extended to include padding on the
+  ;; right, but the first range is not extended to the left to include
+  ;; padding on the left!
+  (should (ert-equal-including-properties
+           (format "%12s" (concat (propertize "01234" 'face 'bold) "56789"))
+           #("  0123456789" 2 7 (face bold))))
+  (should (ert-equal-including-properties
+           (format "%-12s" (concat (propertize "01234" 'face 'bold) "56789"))
+           #("0123456789  " 0 5 (face bold))))
+  (should (ert-equal-including-properties
+           (format "%10s" (concat (propertize "01" 'face 'bold)
+                                  (propertize "23" 'face 'underline)
+                                  "45"))
+           #("    012345" 4 6 (face bold) 6 8 (face underline))))
+  (should (ert-equal-including-properties
+           (format "%-10s" (concat (propertize "01" 'face 'bold)
+                                   (propertize "23" 'face 'underline)
+                                   "45"))
+           #("012345    " 0 2 (face bold) 2 4 (face underline))))
+  (should (ert-equal-including-properties
+           (format "%-10s" (concat (propertize "01" 'face 'bold)
+                                   (propertize "23" 'face 'underline)
+                                   (propertize "45" 'face 'italic)))
+           #("012345    " 0 2 (face bold) 2 4 (face underline) 4 10 (face italic)))))