From: lolligerhans@gmx.de
Date: Mon, 02 Feb 2026 16:21:19 GMT
Subject: [BUG] git log --graph --pretty=format misplaces graph characters when -p given
Message-ID: <trinity-ed0884d3-098e-44be-aa1a-a96f664ce7ca-1770049279182@trinity-msg-rest-gmx-gmx-live-5dd78c558c-fv4g4>

Hello,

Git can pretty-print a commit graph with git log --graph and a custom --pretty
format. I alias some uses of git log --graph --pretty, to which I then want to
manually add "-p" upon invocation.

When using the working command
    git log --graph --pretty='format:%h'
and appending "-p/--patch", the output appears erroneous:
    git log --graph --pretty='format:%h' -p                                 (1)

Expected output:
      1 !    * d0c34d4
      2      | diff --git a/git-bugreport-2026-02-02-1427.txt b/git-bugreport-2026-02-02-1427.txt
      3      | index 5a83af1..2740fd4 100644
      4      | --- a/git-bugreport-2026-02-02-1427.txt
      5      | +++ b/git-bugreport-2026-02-02-1427.txt
      6      | @@ -1,22 +1,53 @@
      7      |  Some context-before line
      8      | -Some removed line
    ---      | ...
    101      | +Some added line
    102      |  Some context-after line
    103 !    | 
    104 !    * 28299b2
    105      | diff --git a/git-bugreport-2026-02-02-1427.txt b/git-bugreport-2026-02-02-1427.txt
    106      | new file mode 100644
    107      | index 0000000..5a83af1
    ---      | ...

Actual output, shortened, with line numbers:
      1 !    * d0c34d4| 
      2      | diff --git a/git-bugreport-2026-02-02-1427.txt b/git-bugreport-2026-02-02-1427.txt
      3      | index 5a83af1..2740fd4 100644
      4      | --- a/git-bugreport-2026-02-02-1427.txt
      5      | +++ b/git-bugreport-2026-02-02-1427.txt
      6      | @@ -1,22 +1,53 @@
      7      |  Some context-before line
      8      | -Some removed line
    ---      | ...
    101      | +Some added line
    102      |  Some context-after line
    103 !    
    104 !    * 28299b2| 
    105      | diff --git a/git-bugreport-2026-02-02-1427.txt b/git-bugreport-2026-02-02-1427.txt
    106      | new file mode 100644
    107      | index 0000000..5a83af1
    ---      | ...

In the actual output, note the trailing "| " sequences in lines {1, 104} and the
missing graph character in line 103. I believe the sequence in line 1 belongs to
line 103.

The actual output looks as if intended to be:
    <asterisk> <format_string>                    <\n> <diff> <\n> <graph_characters> <\n>
but is in the wrong order accidentally:
    <asterisk> <format_string> <graph_characters> <\n> <diff> <\n>                    <\n>
where the graph_characters "| " are misplaced.

Note: I present the reordering of the offending parts as expected, but it may be
more reasonable to expect both not to exist. I.e., no trailing "| " in line 1
and no line 103 entirely.

There are workarounds that hide this problem, with drawbacks. These workarounds
keep the graph is visually intact, but their output may still differ from what
was originally intended:
- Workaround: using "=tformat:" instead of "=format:".
    But: The diff is visually separated apart from the commit it belongs to and
    next to the subsequent commit. I.e., it appears something is still
    misplaced, and the result is better only coincidentally. Compare to
        git log --graph --oneline -p
    which does not use any separation for a --patch.
- Workaround: using "%h%n" instead of "%h".
    Ending the format string with explicit newline curiously fixes the display
    with --patch, but introduces many obsolete lines when used without --patch,
    especially for one-line format strings.

What did you do before the bug happened? (Steps to reproduce your issue)

    1. Ensure at least 2 commits exist. Makes --graph meaningful.
    2. Run the offending command (1):
        git log --graph --pretty='format:%h' -p                             (1)

    Alternatively with shorter output:
        git log --graph --pretty='format:%h' -p --color=always | head -3

What did you expect to happen? (Expected behavior)

    The characters forming edges/vertices of the visual graph are printed at the
    beginning of lines, horizontally left of the other log contents.

What happened instead? (Actual behavior)

    Some characters semantically belonging to the visual graph are printed at
    the end of the line, after the format string.

What's different between what you expected and what actually happened?

    The actual output does not visually form the expected graph. It appears that
    outputs are printed in unintended order.

Anything else you want to add:

    I did not check if "--format" instead of "--pretty=format:" behaves
    identically.

    I grepped for "pretty" in the commits v2.51.0..origin/next and the problem
    appears not to be addressed yet.

    With more branches and colors, the visuals are consistent with what
    I describe above.

    I do not know what is going on here:
        - Using format string "%s%n%b" appears to work fine.
        - Using format string "%s  %b" does not work, but problems start only at
          the second commit, not first.
        - Using format string "  %n%s" does not work.


[System Info]
git version:
git version 2.51.0
$SHELL (typically, interactive shell): /bin/bash

[Enabled Hooks]
not run from a git repository - no hooks to show