Main: Run executables from the temporary directory.

As of May 2020, MiKTeX does no longer support short filenames (aka 8.3 filenames), so if the path to the temporary directory contains short filenames, LaTeX compilation will fail. Unfortunately, in the current framework it seems to be impossible to obtain the full path (with only long filenames) easily.

Resolve this by launching a shell that changes into the temporary directory and then calls the executable from there.

content/main.js

@@ -150,10 +150,7 @@ var tblatex = {
         return process;
       }
       var sanitize_arg = function(arg) {
-        // on Windows the nsIProcess function will add quotes around all arguments with spaces for us
-        if (isWindows)
-          return arg;
-        else if (arg.indexOf(" ") < 0)
+        if (arg.indexOf(" ") < 0)
           return arg;
         else
           return "\""+arg+"\"";
@@ -198,14 +195,40 @@ var tblatex = {
       // script file).
       // Here we get the shell binary and the command line option to call an
       // external program.
+      //
+      // On all platforms, nsIProcess will "escape" the arguments, that is:
+      // - Escape all backslashes (\) and double quotes (") with backslashes (\).
+      // - If an argument contains white-space, then wrap it in double quotes (").
+
       if (isWindows) {
         var env = Components.classes["@mozilla.org/process/environment;1"]
-                  .getService(Components.interfaces.nsIEnvironment);
+            .getService(Components.interfaces.nsIEnvironment);
         var shell_bin = init_file(env.get("COMSPEC"));
-        var shell_option = "/C";
+        // Returned args will be rewritten by nsIProcess to:
+        // /c "echo " \" && cd /d [temp_dir] && [args] && echo \"
+        var prepare_shell_args = (args) => {
+          return ["/c", "echo ", "\"", "&&", "cd", "/d", temp_dir, "&&",
+              ...args, "&&", "echo", "\""];
+        }
       } else {
         var shell_bin = init_file("/bin/sh");
-        var shell_option = "-c";
+        // Returned args will be rewritten by nsIProcess to:
+        // -c "cd [temp_dir] && [args]"
+        var prepare_shell_args = (args) => {
+          return ["-c", "cd " + sanitize_arg(temp_dir) + " && " +
+              args.map(sanitize_arg).join(" ")];
+        }
+      }
+
+      var run_shell_process = (args) => {
+        var args_prepared = prepare_shell_args(args);
+        var shell_process = init_process(shell_bin);
+        shell_process.run(true, args_prepared, args_prepared.length);
+        log += "I ran " + sanitize_arg(shell_bin.path) +
+            (isWindows ? " /c 'cd /d " : " -c 'cd ") + sanitize_arg(temp_dir) +
+            " && " + args.map(sanitize_arg).join(" ") +
+            "' (error code " + shell_process.exitValue + ")\n";
+        return shell_process.exitValue;
       }
 
       var temp_dir = Components.classes["@mozilla.org/file/directory_service;1"].
@@ -241,17 +264,13 @@ var tblatex = {
       converter.writeString(latex_expr);
       converter.close(); // this closes foStream
 
+      var exitValue = run_shell_process([
+        latex_bin.path, "-interaction=batchmode", temp_file_noext+".tex"
+      ]);
 
-      var latex_process = init_process(latex_bin);
-      var latex_args = ["-output-directory="+temp_dir, "-interaction=batchmode", temp_file.path];
-      // This adds quotes around all arguments that contains spaces but only on Unix (on Windows the nsIProcess function will add quotes around all arguments with spaces for us)
-      latex_args = latex_args.map(sanitize_arg);
-      latex_process.run(true, latex_args, latex_args.length);
-      if (debug)
-        log += "I ran "+sanitize_arg(latex_bin.path)+" "+latex_args.join(" ")+" error code "+latex_process.exitValue+"\n";
-      if (latex_process.exitValue) {
+      if (exitValue) {
         st = 1;
-        log += "LaTeX process returned "+latex_process.exitValue+"\nProceeding anyway...\n";
+        log += "LaTeX process returned "+exitValue+"\nProceeding anyway...\n";
       }
 
       ["log", "aux"].forEach(function (ext) {
@@ -342,25 +361,15 @@ var tblatex = {
       if (debug)
         log += "*** Calculated resolution is "+dpi+" dpi\n";
 
-      var shell_process = init_process(shell_bin);
-      var dvipng_args = [dvipng_bin.path, "--depth", "-T", "tight", "-z", "3", "-bg", "Transparent", "-D", dpi.toString(), "-fg", font_color, "-o", png_file.path, dvi_file.path, ">", depth_file.path];
-      // This adds quotes around all arguments that contains spaces but only on Unix (on Windows the nsIProcess function will add quotes around all arguments with spaces for us)
-      dvipng_args = dvipng_args.map(sanitize_arg);
-      if (isWindows) {
-        // The additional echo commands are needed on Windows in order to remove the unwanded backslaches and quotes added by the nsIProcess function ( shell_process.run )
-        var prefix_args = ["echo ", "\"", "&"];
-        var suffix_args = ["&", "echo", "\""];
-        var process_args = [shell_option].concat(prefix_args, dvipng_args, suffix_args);
-      } else {
-        var process_args = [shell_option, dvipng_args.join(" ")];
-      }
-      shell_process.run(true, process_args, process_args.length);
+      var exitValue = run_shell_process([
+        dvipng_bin.path, "--depth", "-T", "tight", "-z", "3", "-bg", "Transparent", "-D", dpi.toString(), "-fg", font_color, "-o", temp_file_noext+".png", temp_file_noext+".dvi", ">", temp_file_noext+"-depth.txt"
+      ]);
+
       if (deletetempfiles) dvi_file.remove(false);
-      if (debug)
-        log += "I ran "+shell_bin.path+" -c '"+dvipng_args.join(" ")+"'\n";
-      if (shell_process.exitValue) {
-        // alert("Latex It! Error\n\nWhen converting the .dvi to a .png bitmap, 'dvipng' failed (Error code: "+shell_process.exitValue+")\n\nSolution:\n\tWe left the .dvi file there:\n\t\t"+temp_file.path+"\n\tTry to run 'dvipng --depth' on it by yourself...");
-        log += "!!! dvipng failed with error code "+shell_process.exitValue+". Aborting.\n";
+
+      if (exitValue) {
+        // alert("Latex It! Error\n\nWhen converting the .dvi to a .png bitmap, 'dvipng' failed (Error code: "+exitValue+")\n\nSolution:\n\tWe left the .dvi file there:\n\t\t"+temp_file.path+"\n\tTry to run 'dvipng --depth' on it by yourself...");
+        log += "!!! dvipng failed with error code "+exitValue+". Aborting.\n";
         return [2, "", 0, log];
       }