[PATCH] diff: add interhunk context config option

The --inter-hunk-context= option was added in commit 6d0e674a5754
("diff: add option to show context between close hunks"). This patch
allows configuring a default for this option.

Cc: René Scharfe <redacted>
Signed-off-by: Vegard Nossum <redacted>
---
 Documentation/diff-options.txt | 2 ++
 diff.c                         | 8 ++++++++
 2 files changed, 10 insertions(+)

diff --git a/Documentation/diff-options.txt b/Documentation/diff-options.txt
index e6215c372..163b65444 100644
--- a/Documentation/diff-options.txt
+++ b/Documentation/diff-options.txt

@@ -511,6 +511,8 @@ endif::git-format-patch[]
 --inter-hunk-context=<lines>::
        Show the context between diff hunks, up to the specified number
        of lines, thereby fusing hunks that are close to each other.
+       Defaults to `diff.interhunkcontext` or 0 if the config option
+       is unset.

 -W::
 --function-context::

diff --git a/diff.c b/diff.c
index 84dba60c4..40b4e6afe 100644
--- a/diff.c
+++ b/diff.c

@@ -33,6 +33,7 @@ static int diff_rename_limit_default = 400;
 static int diff_suppress_blank_empty;
 static int diff_use_color_default = -1;
 static int diff_context_default = 3;
+static int diff_interhunk_context_default = 0;
 static const char *diff_word_regex_cfg;
 static const char *external_diff_cmd_cfg;
 static const char *diff_order_file_cfg;

@@ -248,6 +249,12 @@ int git_diff_ui_config(const char *var, const char *value, void *cb)
                        return -1;
                return 0;
        }
+       if (!strcmp(var, "diff.interhunkcontext")) {
+               diff_interhunk_context_default = git_config_int(var, value);
+               if (diff_interhunk_context_default < 0)
+                       return -1;
+               return 0;
+       }
        if (!strcmp(var, "diff.renames")) {
                diff_detect_rename_default = git_config_rename(var, value);
                return 0;

@@ -3371,6 +3378,7 @@ void diff_setup(struct diff_options *options)
        options->rename_limit = -1;
        options->dirstat_permille = diff_dirstat_permille_default;
        options->context = diff_context_default;
+       options->interhunkcontext = diff_interhunk_context_default;
        options->ws_error_highlight = ws_error_highlight_default;
        DIFF_OPT_SET(options, RENAME_EMPTY);