From 978e222f72fa2127803ef8a7acd60c3475338b2a Mon Sep 17 00:00:00 2001
From: Mike Yuan <me@yhndnzj.com>
Date: Mon, 13 Mar 2023 00:39:07 +0800
Subject: [PATCH] edit-util: rename trim_edit_marker to strip_edit_temp_file

with some minor cleanups
---
 src/shared/edit-util.c | 27 ++++++++++++++-------------
 1 file changed, 14 insertions(+), 13 deletions(-)

diff --git a/src/shared/edit-util.c b/src/shared/edit-util.c
index ab66fc1c1f..0c0e1416fc 100644
--- a/src/shared/edit-util.c
+++ b/src/shared/edit-util.c
@@ -299,21 +299,21 @@ static int run_editor(const EditFileContext *context) {
         return 0;
 }
 
-static int trim_edit_markers(EditFile *e) {
+static int strip_edit_temp_file(EditFile *e) {
         _cleanup_free_ char *old_contents = NULL, *new_contents = NULL;
-        const char *c;
+        const char *stripped;
         int r;
 
         assert(e);
         assert(e->context);
         assert(e->temp);
 
-        /* Trim out the lines between the two markers */
         r = read_full_file(e->temp, &old_contents, NULL);
         if (r < 0)
                 return log_error_errno(r, "Failed to read temporary file \"%s\": %m", e->temp);
 
         if (e->context->marker_start) {
+                /* Trim out the lines between the two markers */
                 char *contents_start, *contents_end;
 
                 assert(e->context->marker_end);
@@ -326,26 +326,27 @@ static int trim_edit_markers(EditFile *e) {
 
                 contents_end = strstr(contents_start, e->context->marker_end);
                 if (contents_end)
-                        contents_end[0] = 0;
+                        *contents_end = '\0';
 
-                c = strstrip(contents_start);
+                stripped = strstrip(contents_start);
         } else
-                c = strstrip(old_contents);
-        if (isempty(c))
-                return 0; /* All gone now */
+                stripped = strstrip(old_contents);
+        if (isempty(stripped))
+                return 0; /* File is empty (has no real changes) */
 
-        new_contents = strjoin(c, "\n"); /* Trim prefix and suffix, but ensure suffixed by single newline */
+        /* Trim prefix and suffix, but ensure suffixed by single newline */
+        new_contents = strjoin(stripped, "\n");
         if (!new_contents)
                 return log_oom();
 
         if (streq(old_contents, new_contents)) /* Don't touch the file if the above didn't change a thing */
-                return 1; /* Unchanged, but good */
+                return 1; /* Contents unchanged after stripping but has changes */
 
         r = write_string_file(e->temp, new_contents, WRITE_STRING_FILE_CREATE | WRITE_STRING_FILE_TRUNCATE | WRITE_STRING_FILE_AVOID_NEWLINE);
         if (r < 0)
                 return log_error_errno(r, "Failed to modify temporary file \"%s\": %m", e->temp);
 
-        return 1; /* Changed, but good */
+        return 1; /* Contents have real changes and are changed after stripping */
 }
 
 int do_edit_files_and_install(EditFileContext *context) {
@@ -367,8 +368,8 @@ int do_edit_files_and_install(EditFileContext *context) {
                 return r;
 
         FOREACH_ARRAY(i, context->files, context->n_files) {
-                /* Always call trim_edit_markers to tell if the temp file is empty */
-                r = trim_edit_markers(i);
+                /* Always call strip_edit_temp_file which will tell if the temp file has actual changes */
+                r = strip_edit_temp_file(i);
                 if (r < 0)
                         return r;
                 if (r == 0) /* temp file doesn't carry actual changes, ignoring */
-- 
2.25.1