Add QPDFArgParser::copyFromOtherTable

include/qpdf/QPDFArgParser.hh

@@ -117,6 +117,14 @@ class QPDFArgParser
     QPDF_DLL
     void addRequiredChoices(
         std::string const& arg, param_arg_handler_t, char const** choices);
+    QPDF_DLL
+
+    // If an option is shared among multiple tables and uses identical
+    // handlers, you can just copy it instead of repeating the
+    // registration call.
+    void copyFromOtherTable(std::string const& arg,
+                            std::string const& other_table);
+
     // The final check handler is called at the very end of argument
     // parsing.
     QPDF_DLL

libqpdf/QPDFArgParser.cc

@@ -153,6 +153,29 @@ QPDFArgParser::addRequiredChoices(
     }
 }
 
+void
+QPDFArgParser::copyFromOtherTable(std::string const& arg,
+                                  std::string const& other_table)
+{
+    if (! this->m->option_tables.count(other_table))
+    {
+        QTC::TC("libtests", "QPDFArgParser copy from unknown");
+        throw std::logic_error(
+            "QPDFArgParser: attempt to copy from unknown table " +
+            other_table);
+    }
+    auto& ot = this->m->option_tables[other_table];
+    if (! ot.count(arg))
+    {
+        QTC::TC("libtests", "QPDFArgParser copy unknown");
+        throw std::logic_error(
+            "QPDFArgParser: attempt to copy unknown argument " + arg +
+            " from table " + other_table);
+    }
+    OptionEntry& oe = registerArg(arg);
+    oe = ot[arg];
+}
+
 void
 QPDFArgParser::addFinalCheck(bare_arg_handler_t handler)
 {
@@ -533,7 +556,8 @@ QPDFArgParser::parseArgs()
             if (oep == this->m->option_table->end())
             {
                 // This is registered automatically, so this can't happen.
-                throw std::logic_error("ArgParser: -- handler not registered");
+                throw std::logic_error(
+                    "QPDFArgParser: -- handler not registered");
             }
         }
         else if ((arg[0] == '-') && (strcmp(arg, "-") != 0))

libtests/arg_parser.cc

@@ -64,6 +64,10 @@ ArgParser::initOptions()
     ap.registerOptionTable("baaa", nullptr);
     ap.addBare("ewe", [this](){ output("you"); });
     ap.addBare("ram", [this](){ output("ram"); });
+    ap.selectMainOptionTable();
+    ap.addBare("sheep", [this](){ this->ap.selectOptionTable("sheep"); });
+    ap.registerOptionTable("sheep", nullptr);
+    ap.copyFromOtherTable("ewe", "baaa");
 }
 
 void
@@ -186,11 +190,28 @@ ArgParser::test_exceptions()
     {
         std::cout << "unknown table: " << e.what() << std::endl;
     }
+    try
+    {
+        ap.copyFromOtherTable("one", "two");
+        assert(false);
+    }
+    catch (std::exception& e)
+    {
+        std::cout << "copy from unknown table: " << e.what() << std::endl;
+    }
+    try
+    {
+        ap.copyFromOtherTable("two", "baaa");
+        assert(false);
+    }
+    catch (std::exception& e)
+    {
+        std::cout << "copy unknown from other table: " << e.what() << std::endl;
+    }
 }
 
 int main(int argc, char* argv[])
 {
-
     ArgParser ap(argc, argv);
     if ((argc == 2) && (strcmp(argv[1], "exceptions") == 0))
     {

libtests/libtests.testcov

@@ -52,3 +52,5 @@ QPDFArgParser help option 0
 QPDFArgParser positional 0
 QPDFArgParser unrecognized 0
 QPDFArgParser complete choices 0
+QPDFArgParser copy from unknown 0
+QPDFArgParser copy unknown 0

libtests/qtest/arg_parser.test

@@ -32,6 +32,7 @@ my @completion_tests = (
     ['arg_parser --quack "user password" ', undef, 'quack-x'],
     ['arg_parser --quack "user pass\'word" ', undef, 'quack-x'],
     ['arg_parser --quack user\ password ', undef, 'quack-x'],
+    ['arg_parser --sheep --', undef, 'sheep'],
     );
 
 foreach my $c (@completion_tests)
@@ -78,6 +79,7 @@ my @arg_tests = (
     ['@quack-xyz --', 0],       # 15
     ['--salad', 2],             # 16
     ['--salad=spinach', 0],     # 17
+    ['--sheep --ewe --', 0],    # 18
     );
 
 for (my $i = 0; $i < scalar(@arg_tests); ++$i)

libtests/qtest/arg_parser/args-18.out

@@ -0,0 +1,2 @@
+you
+total quacks: 0

libtests/qtest/arg_parser/completion-sheep.out

@@ -0,0 +1,3 @@
+--ewe
+!--potato
+!--ram

libtests/qtest/arg_parser/exceptions.out

@@ -2,3 +2,5 @@ duplicate handler: QPDFArgParser: adding a duplicate handler for option potato i
 duplicate handler: QPDFArgParser: adding a duplicate handler for option ram in baaa option table
 duplicate table: QPDFArgParser: registering already registered option table baaa
 unknown table: QPDFArgParser: selecting unregistered option table aardvark
+copy from unknown table: QPDFArgParser: attempt to copy from unknown table two
+copy unknown from other table: QPDFArgParser: attempt to copy unknown argument two from table baaa