Merge pull request #945 from ting-yuan/incoming

Fix the return value of fgets().

3 files changed, 26 insertions, 1 deletions

diff --git a/AUTHORS b/AUTHORS
index 0eb8f7df..0fa41dd2 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -54,4 +54,5 @@ a license to everyone to use it as detailed in LICENSE.)
 * Lorant Pinter <lorant.pinter@prezi.com>
 * Tobias Doerffel <tobias.doerffel@gmail.com>
 * Martin von Gagern <martin@von-gagern.net>
+* Ting-Yuan Huang <thuang@mozilla.com>
 
diff --git a/src/library.js b/src/library.js
index d7efb34f..d5f11cf3 100644
--- a/src/library.js
+++ b/src/library.js
@@ -3170,7 +3170,7 @@ LibraryManager.library = {
     for (var i = 0; i < n - 1 && byte_ != {{{ charCode('\n') }}}; i++) {
       byte_ = _fgetc(stream);
       if (byte_ == -1) {
-        if (streamObj.error) return 0;
+        if (streamObj.error || (streamObj.eof && i == 0)) return 0;
         else if (streamObj.eof) break;
       }
       {{{ makeSetValue('s', 'i', 'byte_', 'i8') }}}
diff --git a/tests/runner.py b/tests/runner.py
index 1a030eae..529dcc48 100755
--- a/tests/runner.py
+++ b/tests/runner.py
@@ -5795,6 +5795,30 @@ def process(filename):
       self.emcc_args += ['--embed-file', 'file_with_byte_234.txt']
       self.do_run(src, '*234\n')
 
+    def test_fgets_eol(self):
+      if self.emcc_args is None: return self.skip('requires emcc')
+      src = r'''
+        #include <stdio.h>
+        char buf[32];
+        int main()
+        {
+          char *r = "SUCCESS";
+          FILE *f = fopen("eol.txt", "r");
+          while (fgets(buf, 32, f) != NULL) {
+            if (buf[0] == '\0') {
+              r = "FAIL";
+              break;
+            }
+          }
+          printf("%s\n", r);
+          fclose(f);
+          return 0;
+        }
+      '''
+      open('eol.txt', 'wb').write('\n')
+      self.emcc_args += ['--embed-file', 'eol.txt']
+      self.do_run(src, 'SUCCESS\n')
+
     def test_folders(self):
       add_pre_run = '''
 def process(filename):