* doc.c: Fix minor memory and file descriptor leaks.

* doc.c (get_doc_string): Fix memory leak when doc file absent.
(get_doc_string, Fsnarf_documentation):
Fix file descriptor leak on error.

src/ChangeLog

 2013-07-18  Paul Eggert  <eggert@cs.ucla.edu>
 
+	* doc.c: Fix minor memory and file descriptor leaks.
+	* doc.c (get_doc_string): Fix memory leak when doc file absent.
+	(get_doc_string, Fsnarf_documentation):
+	Fix file descriptor leak on error.
+
 	* term.c: Fix minor fdopen-related file descriptor leaks.
 	* term.c (Fresume_tty) [!MSDOS]: Close fd if fdopen (fd) fails.
 	(init_tty) [!DOS_NT]: Likewise.  Also close fd if isatty (fd) fails.

src/doc.c

@@ -85,6 +85,7 @@ get_doc_string (Lisp_Object filepos, bool unibyte, bool definition)
   int offset;
   EMACS_INT position;
   Lisp_Object file, tem, pos;
+  ptrdiff_t count;
   USE_SAFE_ALLOCA;
 
   if (INTEGERP (filepos))
@@ -144,9 +145,14 @@ get_doc_string (Lisp_Object filepos, bool unibyte, bool definition)
 	}
 #endif
       if (fd < 0)
-	return concat3 (build_string ("Cannot open doc string file \""),
-			file, build_string ("\"\n"));
+	{
+	  SAFE_FREE ();
+	  return concat3 (build_string ("Cannot open doc string file \""),
+			  file, build_string ("\"\n"));
+	}
     }
+  count = SPECPDL_INDEX ();
+  record_unwind_protect_int (close_file_unwind, fd);
 
   /* Seek only to beginning of disk block.  */
   /* Make sure we read at least 1024 bytes before `position'
@@ -154,13 +160,8 @@ get_doc_string (Lisp_Object filepos, bool unibyte, bool definition)
   offset = min (position, max (1024, position % (8 * 1024)));
   if (TYPE_MAXIMUM (off_t) < position
       || lseek (fd, position - offset, 0) < 0)
-    {
-      emacs_close (fd);
-      error ("Position %"pI"d out of range in doc string file \"%s\"",
-	     position, name);
-    }
-
-  SAFE_FREE ();
+    error ("Position %"pI"d out of range in doc string file \"%s\"",
+	   position, name);
 
   /* Read the doc string into get_doc_string_buffer.
      P points beyond the data just read.  */
@@ -190,10 +191,7 @@ get_doc_string (Lisp_Object filepos, bool unibyte, bool definition)
 	space_left = 1024 * 8;
       nread = emacs_read (fd, p, space_left);
       if (nread < 0)
-	{
-	  emacs_close (fd);
-	  error ("Read error on documentation file");
-	}
+	report_file_error ("Read error on documentation file", file);
       p[nread] = 0;
       if (!nread)
 	break;
@@ -209,7 +207,8 @@ get_doc_string (Lisp_Object filepos, bool unibyte, bool definition)
 	}
       p += nread;
     }
-  emacs_close (fd);
+  unbind_to (count, Qnil);
+  SAFE_FREE ();
 
   /* Sanity checking.  */
   if (CONSP (filepos))
@@ -574,6 +573,7 @@ the same file name is found in the `doc-directory'.  */)
   Lisp_Object sym;
   char *p, *name;
   bool skip_file = 0;
+  ptrdiff_t count;
 
   CHECK_STRING (filename);
 
@@ -615,6 +615,8 @@ the same file name is found in the `doc-directory'.  */)
       report_file_errno ("Opening doc string file", build_string (name),
 			 open_errno);
     }
+  count = SPECPDL_INDEX ();
+  record_unwind_protect_int (close_file_unwind, fd);
   Vdoc_file_name = filename;
   filled = 0;
   pos = 0;
@@ -692,8 +694,7 @@ the same file name is found in the `doc-directory'.  */)
       filled -= end - buf;
       memmove (buf, end, filled);
     }
-  emacs_close (fd);
-  return Qnil;
+  return unbind_to (count, Qnil);
 }
 
 DEFUN ("substitute-command-keys", Fsubstitute_command_keys,