pretty: expand tabs in indented logs to make things line up properly

[thirdparty/git.git] / pretty.c

diff --git a/pretty.c b/pretty.c
index 92b2870a7eabb6a99ffbbcfc222d2ff1c1186fa0..c8b075d91b9dfdcca505c6576b470c8d03e34ac4 100644 (file)
--- a/pretty.c
+++ b/pretty.c
@@ -1629,6 +1629,72 @@ void pp_title_line(struct pretty_print_context *pp,
        strbuf_release(&title);
 }
 
+static int pp_utf8_width(const char *start, const char *end)
+{
+       int width = 0;
+       size_t remain = end - start;
+
+       while (remain) {
+               int n = utf8_width(&start, &remain);
+               if (n < 0 || !start)
+                       return -1;
+               width += n;
+       }
+       return width;
+}
+
+static void strbuf_add_tabexpand(struct strbuf *sb,
+                                const char *line, int linelen)
+{
+       const char *tab;
+
+       while ((tab = memchr(line, '\t', linelen)) != NULL) {
+               int width = pp_utf8_width(line, tab);
+
+               /*
+                * If it wasn't well-formed utf8, or it
+                * had characters with badly defined
+                * width (control characters etc), just
+                * give up on trying to align things.
+                */
+               if (width < 0)
+                       break;
+
+               /* Output the data .. */
+               strbuf_add(sb, line, tab - line);
+
+               /* .. and the de-tabified tab */
+               strbuf_addchars(sb, ' ', 8 - (width % 8));
+
+               /* Skip over the printed part .. */
+               linelen -= tab + 1 - line;
+               line = tab + 1;
+       }
+
+       /*
+        * Print out everything after the last tab without
+        * worrying about width - there's nothing more to
+        * align.
+        */
+       strbuf_add(sb, line, linelen);
+}
+
+/*
+ * pp_handle_indent() prints out the intendation, and
+ * the whole line (without the final newline), after
+ * de-tabifying.
+ */
+static void pp_handle_indent(struct pretty_print_context *pp,
+                            struct strbuf *sb, int indent,
+                            const char *line, int linelen)
+{
+       strbuf_addchars(sb, ' ', indent);
+       if (pp->expand_tabs_in_log)
+               strbuf_add_tabexpand(sb, line, linelen);
+       else
+               strbuf_add(sb, line, linelen);
+}
+
 void pp_remainder(struct pretty_print_context *pp,
                  const char **msg_p,
                  struct strbuf *sb,
@@ -1653,8 +1719,9 @@ void pp_remainder(struct pretty_print_context *pp,
 
                strbuf_grow(sb, linelen + indent + 20);
                if (indent)
-                       strbuf_addchars(sb, ' ', indent);
-               strbuf_add(sb, line, linelen);
+                       pp_handle_indent(pp, sb, indent, line, linelen);
+               else
+                       strbuf_add(sb, line, linelen);
                strbuf_addch(sb, '\n');
        }
 }