Merge branch 'jk/more-comments-on-textconv' into maint

The memory ownership rule of fill_textconv() API, which was a bit
tricky, has been documented a bit better.

* jk/more-comments-on-textconv:
diff: clarify textconv interface

diff --git a/diff.c b/diff.c
index 2136b6970b3a9751a3ec420bac61e9baa08df9b0..a088e269b42d4af24a756c991bf60dca8eb4153d 100644 (file)
--- a/diff.c
+++ b/diff.c
@@ -5085,7 +5085,7 @@ size_t fill_textconv(struct userdiff_driver *driver,
 {
        size_t size;
 
-       if (!driver || !driver->textconv) {
+       if (!driver) {
                if (!DIFF_FILE_VALID(df)) {
                        *outbuf = "";
                        return 0;
@@ -5096,6 +5096,9 @@ size_t fill_textconv(struct userdiff_driver *driver,
                return df->size;
        }
 
+       if (!driver->textconv)
+               die("BUG: fill_textconv called with non-textconv driver");
+
        if (driver->textconv_cache && df->sha1_valid) {
                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
                                          &size);

diff --git a/diff.h b/diff.h
index 70b2d70d64e1e47da617f51b8385870a22e92f40..4505b4d91dd0985b25f5ba8c087c5afe34166631 100644 (file)
--- a/diff.h
+++ b/diff.h
@@ -349,10 +349,26 @@ extern void diff_no_index(struct rev_info *, int, const char **);
 
 extern int index_differs_from(const char *def, int diff_flags);
 
+/*
+ * Fill the contents of the filespec "df", respecting any textconv defined by
+ * its userdiff driver.  The "driver" parameter must come from a
+ * previous call to get_textconv(), and therefore should either be NULL or have
+ * textconv enabled.
+ *
+ * Note that the memory ownership of the resulting buffer depends on whether
+ * the driver field is NULL. If it is, then the memory belongs to the filespec
+ * struct. If it is non-NULL, then "outbuf" points to a newly allocated buffer
+ * that should be freed by the caller.
+ */
 extern size_t fill_textconv(struct userdiff_driver *driver,
                            struct diff_filespec *df,
                            char **outbuf);
 
+/*
+ * Look up the userdiff driver for the given filespec, and return it if
+ * and only if it has textconv enabled (otherwise return NULL). The result
+ * can be passed to fill_textconv().
+ */
 extern struct userdiff_driver *get_textconv(struct diff_filespec *one);
 
 extern int parse_rename_score(const char **cp_p);

diff --git a/userdiff.h b/userdiff.h
index 4a7e78ffbcc6d552a39dcccd9008d6c11919e432..2ef0ce545278ea2f40526c42303c541736643bd5 100644 (file)
--- a/userdiff.h
+++ b/userdiff.h
@@ -23,6 +23,10 @@ int userdiff_config(const char *k, const char *v);
 struct userdiff_driver *userdiff_find_by_name(const char *name);
 struct userdiff_driver *userdiff_find_by_path(const char *path);
 
+/*
+ * Initialize any textconv-related fields in the driver and return it, or NULL
+ * if it does not have textconv enabled at all.
+ */
 struct userdiff_driver *userdiff_get_textconv(struct userdiff_driver *driver);
 
 #endif /* USERDIFF */