survive to width.precision screw ups in %s

mongoose.c

@@ -2968,7 +2968,12 @@ size_t mg_vxprintf(void (*out)(char, void *), void *param, const char *fmt,
         n++;
       } else if (c == 's') {
         char *p = va_arg(*ap, char *);
-        if (pr == ~0U) pr = p == NULL ? 0 : strlen(p);
+        if (p != NULL && pr != ~0U) {
+          for (j = 0; j < pr && p[j] != '\0'; j++) ;  // portable strnlen()
+          pr = j;
+        } else {
+          pr = p == NULL ? 0 : strlen(p);
+        }
         for (j = 0; !minus && pr < w && j + pr < w; j++)
           n += scpy(out, param, &pad, 1);
         n += scpy(out, param, p, pr);
@@ -4484,15 +4489,13 @@ static void listdir(struct mg_connection *c, struct mg_http_message *hm,
 static bool uri2path(const char *r, struct mg_str uri, char *buf, size_t len) {
   struct mg_str k, v, part, s = mg_str(r), u = {NULL, 0}, d = u;
   size_t n;
-  bool matched = false;
   while (mg_span(s, &part, &s, ',')) {
     if (!mg_span(part, &k, &v, '=')) k = part, v = mg_str_n(NULL, 0);
     if (v.len == 0) v = k, k = mg_str("/"), u = k, d = v;
     if (uri.len < k.len) continue;
     if (mg_strcmp(k, mg_str_n(uri.buf, k.len)) != 0) continue;
-    u = k, d = v, matched = true;
+    u = k, d = v;
   }
-  if (!matched) return false;
   n = mg_snprintf(buf, len, "%.*s", (int) d.len, d.buf);
   if (len == 0 || n + 2 >= len) return false;  // Path overflow
   if (n > 0 && buf[n - 1] != '/') buf[n++] = '/', buf[n] = '\0';  // Add slash

mongoose.h

@@ -4109,8 +4109,6 @@ struct mg_dash {
   struct mg_fs *upload_fs;  // FS for uploads/listing, default &mg_fs_posix
   // Resolves the built-in file manager's root dir for user u, e.g. per-user
   // upload directories. NULL: file manager disabled
-  // - The returned directory must be nonempty and must not contain ',' or '=',
-  // because it is used as an mg_http_serve_opts::root_dir mapping target.
   bool (*files_dir)(const struct mg_dash_user *u, char *buf, size_t len);
 };
 

src/dash.h

@@ -96,8 +96,6 @@ struct mg_dash {
   struct mg_fs *upload_fs;  // FS for uploads/listing, default &mg_fs_posix
   // Resolves the built-in file manager's root dir for user u, e.g. per-user
   // upload directories. NULL: file manager disabled
-  // - The returned directory must be nonempty and must not contain ',' or '=',
-  // because it is used as an mg_http_serve_opts::root_dir mapping target.
   bool (*files_dir)(const struct mg_dash_user *u, char *buf, size_t len);
 };
 

src/fmt.c

@@ -214,7 +214,12 @@ size_t mg_vxprintf(void (*out)(char, void *), void *param, const char *fmt,
         n++;
       } else if (c == 's') {
         char *p = va_arg(*ap, char *);
-        if (pr == ~0U) pr = p == NULL ? 0 : strlen(p);
+        if (p != NULL && pr != ~0U) {
+          for (j = 0; j < pr && p[j] != '\0'; j++) ;  // portable strnlen()
+          pr = j;
+        } else {
+          pr = p == NULL ? 0 : strlen(p);
+        }
         for (j = 0; !minus && pr < w && j + pr < w; j++)
           n += scpy(out, param, &pad, 1);
         n += scpy(out, param, p, pr);

src/http.c

@@ -734,15 +734,13 @@ static void listdir(struct mg_connection *c, struct mg_http_message *hm,
 static bool uri2path(const char *r, struct mg_str uri, char *buf, size_t len) {
   struct mg_str k, v, part, s = mg_str(r), u = {NULL, 0}, d = u;
   size_t n;
-  bool matched = false;
   while (mg_span(s, &part, &s, ',')) {
     if (!mg_span(part, &k, &v, '=')) k = part, v = mg_str_n(NULL, 0);
     if (v.len == 0) v = k, k = mg_str("/"), u = k, d = v;
     if (uri.len < k.len) continue;
     if (mg_strcmp(k, mg_str_n(uri.buf, k.len)) != 0) continue;
-    u = k, d = v, matched = true;
+    u = k, d = v;
   }
-  if (!matched) return false;
   n = mg_snprintf(buf, len, "%.*s", (int) d.len, d.buf);
   if (len == 0 || n + 2 >= len) return false;  // Path overflow
   if (n > 0 && buf[n - 1] != '/') buf[n++] = '/', buf[n] = '\0';  // Add slash

test/unit_test.c

@@ -1475,11 +1475,6 @@ static void h4(struct mg_connection *c, int ev, void *ev_data) {
       opts.root_dir = "/a=./data";
       opts.page404 = "./data/404.html";  // existing 404 page
       mg_http_serve_dir(c, hm, &opts);
-    } else if (mg_match(hm->uri, mg_str("/unmapped"), NULL)) {
-      struct mg_http_serve_opts opts;
-      memset(&opts, 0, sizeof(opts));
-      opts.root_dir = "/a=./data";
-      mg_http_serve_dir(c, hm, &opts);
     } else if (mg_match(hm->uri, mg_str("/b/#"), NULL)) {
       struct mg_http_serve_opts opts;
       memset(&opts, 0, sizeof(opts));
@@ -1507,7 +1502,6 @@ static void test_http_404(void) {
   ASSERT(cmpbody(buf, "hello\n") == 0);
   ASSERT(fetch(&mgr, buf, url, "GET /a/a.txt HTTP/1.0\n\n") == 200);
   ASSERT(cmpbody(buf, "hello\n") == 0);
-  ASSERT(fetch(&mgr, buf, url, "GET /unmapped HTTP/1.0\n\n") == 400);
   ASSERT(fetch(&mgr, buf, url, "GET /b/a.txt HTTP/1.0\n\n") == 200);
   ASSERT(cmpbody(buf, "hello\n") == 0);
 
@@ -2405,10 +2399,15 @@ static void test_str(void) {
   ASSERT(sn("%.*s", 1, "ab"));
   ASSERT(sn("%.1s", "ab"));
   ASSERT(sn("%.99s", "a"));
+  ASSERT(sn("%10.8s", "abc"));
+  ASSERT(sn("%-6.4s", "ab"));
+  ASSERT(sn("%5.1s", ""));
   ASSERT(sn("%11s", "a"));
   ASSERT(sn("%s", "a\0b"));
   ASSERT(sn("%2s", "a"));
   ASSERT(sn("%.*s", 3, "a\0b"));
+  ASSERT(mg_snprintf(NULL, 0, "%.8s", (char *) NULL) == 0);
+  ASSERT(mg_snprintf(NULL, 0, "%8.4s", (char *) NULL) == 8);
   ASSERT(sn("%d", 7));
   ASSERT(sn("%d", 123));
 #if MG_ARCH == MG_ARCH_UNIX