neovim

commit 4bd0611d7b07b56fc5a9e121669a313166ba540f
parent bfa0bc7df0ca527fcec49dbd2055f1bac438663e
Author: zeertzjq <zeertzjq@outlook.com>
Date:   Tue, 28 Feb 2023 19:23:28 +0800

vim-patch:9.0.0803: readblob() cannot read from character device

Problem:    readblob() cannot read from character device.
Solution:   Use S_ISCHR() to not check the size. (Ken Takata, closes vim/vim#11407)

https://github.com/vim/vim/commit/43625762a9751cc6e6e4d8f54fbc8b82d98fb20d

S_ISCHR is always defined in Nvim.

Co-authored-by: K.Takata <kentkt@csc.jp>

Diffstat:
M
runtime/doc/builtin.txt
 | 
7
++++++-
M
src/nvim/eval.c
 | 
5
+++--
M
src/nvim/testdir/test_blob.vim
 | 
5
+++++

3 files changed, 14 insertions(+), 3 deletions(-)
diff --git a/runtime/doc/builtin.txt b/runtime/doc/builtin.txt
@@ -6164,7 +6164,12 @@ readblob({fname} [, {offset} [, {size}]])			*readblob()*
 			readblob('file.bin', 0, 100)
 <		If {size} is -1 or omitted, the whole data starting from
 		{offset} will be read.
-		When the file can't be opened an error message is given and
+		This can be also used to read the data from a character device
+		on Unix when {size} is explicitly set.  Only if the device
+		supports seeking {offset} can be used.  Otherwise it should be
+		zero.  E.g. to read 10 bytes from a serial console: >
+			readblob('/dev/ttyS0', 0, 10)
+<		When the file can't be opened an error message is given and
 		the result is an empty |Blob|.
 		When trying to read bytes beyond the end of the file the
 		result is an empty blob.
diff --git a/src/nvim/eval.c b/src/nvim/eval.c
@@ -5893,10 +5893,11 @@ int read_blob(FILE *const fd, typval_T *rettv, off_T offset, off_T size_arg)
   }
   // Trying to read bytes that aren't there results in an empty blob, not an
   // error.
-  if (size < 0 || size > (off_T)os_fileinfo_size(&file_info)) {
+  if (size < 0 || (!S_ISCHR(file_info.stat.st_mode)
+                   && size > (off_T)os_fileinfo_size(&file_info))) {
     return OK;
   }
-  if (vim_fseek(fd, offset, whence) != 0) {
+  if (offset != 0 && vim_fseek(fd, offset, whence) != 0) {
     return OK;
   }
 
diff --git a/src/nvim/testdir/test_blob.vim b/src/nvim/testdir/test_blob.vim
@@ -459,6 +459,11 @@ func Test_blob_read_write()
   END
   call CheckLegacyAndVim9Success(lines)
 
+  if filereadable('/dev/random')
+    let b = readblob('/dev/random', 0, 10)
+    call assert_equal(10, len(b))
+  endif
+
   call assert_fails("call readblob('notexist')", 'E484:')
   " TODO: How do we test for the E485 error?