Merge pull request #888 from pkgw/pipe-input-workaround

Warn on attempted pipe inputs

Author: pkgw

crates/bundles/src/itar.rs

@@ -159,35 +159,40 @@ impl CacheBackend for IndexedTarBackend {
         let mut overall_failed = true;
         let mut any_failed = false;
 
-        for _ in 0..MAX_HTTP_ATTEMPTS {
-            let mut stream = match self.reader.read_range(info.offset, n) {
-                Ok(r) => r,
-                Err(e) => {
-                    tt_warning!(status, "failure requesting \"{}\" from network", name; e);
+        // Our HTTP implementation actually has problems with zero-sized ranged
+        // reads (Azure gives us a 200 response, which we don't properly
+        // handle), but when the file is 0-sized we're all set anyway!
+        if n > 0 {
+            for _ in 0..MAX_HTTP_ATTEMPTS {
+                let mut stream = match self.reader.read_range(info.offset, n) {
+                    Ok(r) => r,
+                    Err(e) => {
+                        tt_warning!(status, "failure requesting \"{}\" from network", name; e);
+                        any_failed = true;
+                        continue;
+                    }
+                };
+
+                if let Err(e) = stream.read_to_end(&mut buf) {
+                    tt_warning!(status, "failure downloading \"{}\" from network", name; e.into());
                     any_failed = true;
                     continue;
                 }
-            };
 
-            if let Err(e) = stream.read_to_end(&mut buf) {
-                tt_warning!(status, "failure downloading \"{}\" from network", name; e.into());
-                any_failed = true;
-                continue;
+                overall_failed = false;
+                break;
             }
 
-            overall_failed = false;
-            break;
-        }
-
-        if overall_failed {
-            bail!(
-                "failed to retrieve \"{}\" from the network; \
-             this most probably is not Tectonic's fault \
-             -- please check your network connection.",
-                name
-            );
-        } else if any_failed {
-            tt_note!(status, "download succeeded after retry");
+            if overall_failed {
+                bail!(
+                    "failed to retrieve \"{}\" from the network; \
+                this most probably is not Tectonic's fault \
+                -- please check your network connection.",
+                    name
+                );
+            } else if any_failed {
+                tt_note!(status, "download succeeded after retry");
+            }
         }
 
         Ok(buf)

crates/engine_xetex/xetex/xetex-io.c

@@ -24,10 +24,21 @@ tt_xetex_open_input (int filefmt)
 {
     rust_input_handle_t handle;
 
-    if (filefmt == TTBC_FILE_FORMAT_TECTONIC_PRIMARY)
+    if (filefmt == TTBC_FILE_FORMAT_TECTONIC_PRIMARY) {
         handle = ttstub_input_open_primary ();
-    else
+    } else if (name_of_file[0] == '|') {
+        // Tectonic TODO: issue #859. In mainline XeTeX, a pipe symbol indicates
+        // piped input from an external command via `popen()`. Now that we have
+        // shell-escape support we could also support this, but we don't have a
+        // real implementation yet. For now, issue a warning.
+        print_nl_cstr("Warning: ");
+        diagnostic_begin_capture_warning_here();
+        print_cstr("piped inputs from external commands are not implemented in Tectonic");
+        capture_to_diagnostic(NULL);
+        return NULL;
+    } else {
         handle = ttstub_input_open (name_of_file, (ttbc_file_format) filefmt, 0);
+    }
 
     if (handle == NULL)
         return NULL;

tests/tex-outputs.rs

@@ -288,6 +288,13 @@ fn pdfoutput() {
     TestCase::new("pdfoutput").go()
 }
 
+#[test]
+fn pipe_input() {
+    TestCase::new("pipe_input")
+        .expect_msg("failed to open input file \"|pipeproblems\"")
+        .go()
+}
+
 #[test]
 fn png_formats() {
     TestCase::new("png_formats").check_pdf(true).go()

tests/tex-outputs/pipe_input.log

@@ -0,0 +1,3 @@
+**
+(pipe_input.tex
+Warning: piped inputs from external commands are not implemented in Tectonic

tests/tex-outputs/pipe_input.tex

@@ -0,0 +1,2 @@
+\input{|pipeproblems}
+\end