gout

commit d3db909b464737863e9b54ae7c28393f0871aed4
parent c4edd894077a09547707f9ff76e4e188b361354b
Author: Chris Bracken <chris@bracken.jp>
Date:   Fri, 20 Feb 2026 18:08:46 +0900

utils: improve relpath_from_dir

Diffstat:
M
src/utils.c
 | 
33
+++++++++++++++++++++++++--------
M
src/utils_tests.c
 | 
78
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-------------------

2 files changed, 84 insertions(+), 27 deletions(-)
diff --git a/src/utils.c b/src/utils.c
@@ -120,22 +120,39 @@ bool is_safe_mailto(const char* email) {
 }
 
 char* relpath_from_dir(const char* dir) {
-  size_t num_components = 1;
-  if (strcmp(dir, ".") != 0) {
-    for (const char* p = dir; *p != '\0'; p++) {
-      if (*p == '/') {
-        num_components++;
-      }
+  if (!dir || dir[0] == '\0' || strcmp(dir, ".") == 0) {
+    return estrdup("");
+  }
+
+  size_t depth = 0;
+  const char* p = dir;
+  /* Skip leading slashes. */
+  while (*p == '/') {
+    p++;
+  }
+
+  /* For each component, increment depth. Skip repeated slashes. */
+  while (*p != '\0') {
+    depth++;
+    while (*p != '\0' && *p != '/') {
+      p++;
+    }
+    while (*p == '/') {
+      p++;
     }
   }
+  if (depth == 0) {
+    return estrdup("");
+  }
 
+  /* Output the appropriate number of ../ for the depth. */
   const char segment[] = "../";
   const size_t segment_len = sizeof(segment) - 1;
-  size_t relpath_size = (num_components * segment_len) + 1;
+  size_t relpath_size = (depth * segment_len) + 1;
 
   char* relpath = ecalloc(relpath_size, 1);
   char* ptr = relpath;
-  for (size_t i = 0; i < num_components; i++) {
+  for (size_t i = 0; i < depth; i++) {
     memcpy(ptr, segment, segment_len);
     ptr += segment_len;
   }
diff --git a/src/utils_tests.c b/src/utils_tests.c
@@ -70,32 +70,72 @@ UTEST(is_safe_mailto, RejectsInvalidCharacters) {
   EXPECT_FALSE(is_safe_mailto("test@example.com\n"));
 }
 
-UTEST(relpath_from_dir, SingleDirectory) {
-  char* result = relpath_from_dir("folder");
-  ASSERT_STREQ("../", result);
-  free(result);
+UTEST(relpath_from_dir, EmptyOrNull) {
+  char* r1 = relpath_from_dir("");
+  EXPECT_STREQ("", r1);
+  free(r1);
+
+  char* r2 = relpath_from_dir(NULL);
+  EXPECT_STREQ("", r2);
+  free(r2);
+
+  char* r3 = relpath_from_dir(".");
+  EXPECT_STREQ("", r3);
+  free(r3);
 }
 
-UTEST(relpath_from_dir, MultipleDirectories) {
-  char* result = relpath_from_dir("path/to/somewhere");
-  ASSERT_STREQ("../../../", result);
-  free(result);
+UTEST(relpath_from_dir, SingleDirectory) {
+  char* r1 = relpath_from_dir("foo");
+  EXPECT_STREQ("../", r1);
+  free(r1);
+
+  char* r2 = relpath_from_dir("foo/");
+  EXPECT_STREQ("../", r2);
+  free(r2);
 }
 
-UTEST(relpath_from_dir, CurrentDirectoryLiteral) {
-  char* result = relpath_from_dir(".");
-  ASSERT_STREQ("../", result);
-  free(result);
+UTEST(relpath_from_dir, LeadingSlash) {
+  char* r2 = relpath_from_dir("/foo");
+  EXPECT_STREQ("../", r2);
+  free(r2);
 }
 
 UTEST(relpath_from_dir, TrailingSlash) {
-  char* result = relpath_from_dir("folder/");
-  ASSERT_STREQ("../../", result);
-  free(result);
+  char* r2 = relpath_from_dir("foo/");
+  EXPECT_STREQ("../", r2);
+  free(r2);
 }
 
-UTEST(relpath_from_dir, RootPath) {
-  char* result = relpath_from_dir("/");
-  ASSERT_STREQ("../../", result);
-  free(result);
+UTEST(relpath_from_dir, NestedDirectories) {
+  char* r1 = relpath_from_dir("foo/bar");
+  EXPECT_STREQ("../../", r1);
+  free(r1);
+
+  char* r2 = relpath_from_dir("foo/bar/baz");
+  EXPECT_STREQ("../../../", r2);
+  free(r2);
+
+  char* r3 = relpath_from_dir("a/b/c/d/e");
+  EXPECT_STREQ("../../../../../", r3);
+  free(r3);
+}
+
+UTEST(relpath_from_dir, MultipleSlashes) {
+  char* r1 = relpath_from_dir("foo//bar");
+  EXPECT_STREQ("../../", r1);
+  free(r1);
+
+  char* r2 = relpath_from_dir("//foo///bar//");
+  EXPECT_STREQ("../../", r2);
+  free(r2);
+}
+
+UTEST(relpath_from_dir, AbsolutePath) {
+  char* r1 = relpath_from_dir("/foo");
+  EXPECT_STREQ("../", r1);
+  free(r1);
+
+  char* r2 = relpath_from_dir("/");
+  EXPECT_STREQ("", r2);
+  free(r2);
 }