mailmap: refactor mailmap parsing for non-file sources

The read_single_mailmap function opens a mailmap file and
parses each line. In preparation for having non-file
mailmaps, let's pull out the line-parsing logic into its own
function (read_mailmap_line), and rename the file-parsing
function to match (read_mailmap_file).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

mailmap.c

@@ -129,44 +129,50 @@ static char *parse_name_and_email(char *buffer, char **name,
 	return (*right == '\0' ? NULL : right);
 }
 
-static int read_single_mailmap(struct string_list *map, const char *filename, char **repo_abbrev)
+static void read_mailmap_line(struct string_list *map, char *buffer,
+			      char **repo_abbrev)
+{
+	char *name1 = NULL, *email1 = NULL, *name2 = NULL, *email2 = NULL;
+	if (buffer[0] == '#') {
+		static const char abbrev[] = "# repo-abbrev:";
+		int abblen = sizeof(abbrev) - 1;
+		int len = strlen(buffer);
+
+		if (!repo_abbrev)
+			return;
+
+		if (len && buffer[len - 1] == '\n')
+			buffer[--len] = 0;
+		if (!strncmp(buffer, abbrev, abblen)) {
+			char *cp;
+
+			if (repo_abbrev)
+				free(*repo_abbrev);
+			*repo_abbrev = xmalloc(len);
+
+			for (cp = buffer + abblen; isspace(*cp); cp++)
+				; /* nothing */
+			strcpy(*repo_abbrev, cp);
+		}
+		return;
+	}
+	if ((name2 = parse_name_and_email(buffer, &name1, &email1, 0)) != NULL)
+		parse_name_and_email(name2, &name2, &email2, 1);
+
+	if (email1)
+		add_mapping(map, name1, email1, name2, email2);
+}
+
+static int read_mailmap_file(struct string_list *map, const char *filename,
+			     char **repo_abbrev)
 {
 	char buffer[1024];
 	FILE *f = (filename == NULL ? NULL : fopen(filename, "r"));
 
 	if (f == NULL)
 		return 1;
-	while (fgets(buffer, sizeof(buffer), f) != NULL) {
-		char *name1 = NULL, *email1 = NULL, *name2 = NULL, *email2 = NULL;
-		if (buffer[0] == '#') {
-			static const char abbrev[] = "# repo-abbrev:";
-			int abblen = sizeof(abbrev) - 1;
-			int len = strlen(buffer);
-
-			if (!repo_abbrev)
-				continue;
-
-			if (len && buffer[len - 1] == '\n')
-				buffer[--len] = 0;
-			if (!strncmp(buffer, abbrev, abblen)) {
-				char *cp;
-
-				if (repo_abbrev)
-					free(*repo_abbrev);
-				*repo_abbrev = xmalloc(len);
-
-				for (cp = buffer + abblen; isspace(*cp); cp++)
-					; /* nothing */
-				strcpy(*repo_abbrev, cp);
-			}
-			continue;
-		}
-		if ((name2 = parse_name_and_email(buffer, &name1, &email1, 0)) != NULL)
-			parse_name_and_email(name2, &name2, &email2, 1);
-
-		if (email1)
-			add_mapping(map, name1, email1, name2, email2);
-	}
+	while (fgets(buffer, sizeof(buffer), f) != NULL)
+		read_mailmap_line(map, buffer, repo_abbrev);
 	fclose(f);
 	return 0;
 }
@@ -175,8 +181,8 @@ int read_mailmap(struct string_list *map, char **repo_abbrev)
 {
 	map->strdup_strings = 1;
 	/* each failure returns 1, so >1 means both calls failed */
-	return read_single_mailmap(map, ".mailmap", repo_abbrev) +
-	       read_single_mailmap(map, git_mailmap_file, repo_abbrev) > 1;
+	return read_mailmap_file(map, ".mailmap", repo_abbrev) +
+	       read_mailmap_file(map, git_mailmap_file, repo_abbrev) > 1;
 }
 
 void clear_mailmap(struct string_list *map)