diff-tree: prettify output slightly

Make the commit explanation buffer larger, and make sure that if
we truncate it, we put a "..." marker there to visually tell people
about the truncation (tested with a much smaller buffer to make
sure it looks sane).

Also make sure that the explanation is properly line-terminated,
and add an extra newline iff we have a diff.

diff --git a/diff-tree.c b/diff-tree.c
index 233a250..868404f 100644 (file)
--- a/diff-tree.c
+++ b/diff-tree.c
@@ -332,7 +332,7 @@ static int add_author_info(char *buf, const char *line, int len)
 
 static char *generate_header(const char *commit, const char *parent, const char *msg, unsigned long len)
 {
-       static char this_header[1000];
+       static char this_header[16384];
        int offset;
 
        offset = sprintf(this_header, "%s%s (from %s)\n", header_prefix, commit, parent);
@@ -345,8 +345,16 @@ static char *generate_header(const char *commit, const char *parent, const char
 
                        if (!linelen)
                                break;
-                       if (offset + linelen + 10 > sizeof(this_header))
+
+                       /*
+                        * We want some slop for indentation and a possible
+                        * final "...". Thus the "+ 20".
+                        */
+                       if (offset + linelen + 20 > sizeof(this_header)) {
+                               memcpy(this_header + offset, "    ...\n", 8);
+                               offset += 8;
                                break;
+                       }
 
                        msg += linelen;
                        len -= linelen;
@@ -361,7 +369,12 @@ static char *generate_header(const char *commit, const char *parent, const char
                        memcpy(this_header + offset + 4, line, linelen);
                        offset += linelen + 4;
                }
-               this_header[offset++] = '\n';
+               /* Make sure there is an EOLN */
+               if (this_header[offset-1] != '\n')
+                       this_header[offset++] = '\n';
+               /* Add _another_ EOLN if we are doing diff output */
+               if (!silent)
+                       this_header[offset++] = '\n';
                this_header[offset] = 0;
        }