Always use 0,1,2 for stdio fileno when non-native.

This code was originally removed in 7e024a7 to fix #2690, but childprocess was no longer able to launch a subprocess (#4122). Until Windows has native, we need this code in place...and may always need it for non-native setups, to keep stdio fileno sane. Fixes #4122.
jruby · Sep 1, 2016 · 1a977d5 · 1a977d5
1 parent d5f6fca
commit 1a977d5
Showing 1 changed file with 18 additions and 0 deletions.
diff --git a/core/src/main/java/org/jruby/RubyIO.java b/core/src/main/java/org/jruby/RubyIO.java
@@ -187,6 +187,14 @@ public static RubyIO prepStdio(Ruby runtime, InputStream f, Channel c, int fmode
 
         fptr = io.getOpenFileChecked();
 
+        // If we can't use native IO, always force stdio to expected fileno.
+        if (!runtime.getPosix().isNative() || Platform.IS_WINDOWS) {
+            // Use standard stdio filenos if we're using System.in et al.
+            if (f == System.in) {
+                fptr.fd().realFileno = 0;
+            }
+        }
+
         prepStdioEcflags(fptr, fmode);
         fptr.stdio_file = f;
 
@@ -201,6 +209,16 @@ public static RubyIO prepStdio(Ruby runtime, OutputStream f, Channel c, int fmod
 
         fptr = io.getOpenFileChecked();
 
+        // If we can't use native IO, always force stdio to expected fileno.
+        if (!runtime.getPosix().isNative() || Platform.IS_WINDOWS) {
+            // Use standard stdio filenos if we're using System.in et al.
+            if (f == System.out) {
+                fptr.fd().realFileno = 1;
+            } else if (f == System.err) {
+                fptr.fd().realFileno = 2;
+            }
+        }
+
         prepStdioEcflags(fptr, fmode);
         fptr.stdio_file = f;