Add --no-warn option to suppress warnings (fixes #232)

ChangeLog

@@ -1,5 +1,9 @@
 2018-08-12  Jay Berkenbilt  <ejb@ql.org>
 
+	* qpdf command line: add --no-warn option to suppress issuing
+	warning messages. If there are any conditions that would have
+	caused warnings to be issued, the exit status is still 3.
+
 	* Rewrite the internals of Pl_Buffer to be much more efficient in
 	use of memory at a very slight performance cost. The old
 	implementation could cause memory usage to go out of control for

qpdf/qpdf.cc

@@ -61,6 +61,7 @@ struct Options
         split_pages(0),
         verbose(false),
         progress(false),
+        suppress_warnings(false),
         copy_encryption(false),
         encryption_file(0),
         encryption_file_password(0),
@@ -125,6 +126,7 @@ struct Options
     int split_pages;
     bool verbose;
     bool progress;
+    bool suppress_warnings;
     bool copy_encryption;
     char const* encryption_file;
     char const* encryption_file_password;
@@ -262,6 +264,7 @@ Basic Options\n\
 --password=password     specify a password for accessing encrypted files\n\
 --verbose               provide additional informational output\n\
 --progress              give progress indicators while writing output\n\
+--no-warn               suppress warnings\n\
 --linearize             generated a linearized (web optimized) file\n\
 --copy-encryption=file  copy encryption parameters from specified file\n\
 --encryption-file-password=password\n\
@@ -515,8 +518,9 @@ page content stream.  This attempt will be made even if it is not a\n\
 page content stream, in which case it will produce unusable results.\n\
 \n\
 Ordinarily, qpdf exits with a status of 0 on success or a status of 2\n\
-if any errors occurred.  In --check mode, if there were warnings but not\n\
+if any errors occurred.  If there were warnings but not errors, qpdf\n\
-errors, qpdf exits with a status of 3.\n\
+exits with a status of 3. If warnings would have been issued but --no-warn\n\
+was given, an exit status of 3 is still used.\n\
 \n";
 
 void usage(std::string const& msg)
@@ -1676,6 +1680,10 @@ static void parse_options(int argc, char* argv[], Options& o)
             {
                 o.progress = true;
             }
+            else if (strcmp(arg, "no-warn") == 0)
+            {
+                o.suppress_warnings = true;
+            }
             else if (strcmp(arg, "deterministic-id") == 0)
             {
                 o.deterministic_id = true;
@@ -1832,6 +1840,10 @@ static void set_qpdf_options(QPDF& pdf, Options& o)
     {
         pdf.setPasswordIsHexKey(true);
     }
+    if (o.suppress_warnings)
+    {
+        pdf.setSuppressWarnings(true);
+    }
 }
 
 static void do_check(QPDF& pdf, Options& o, int& exit_code)
@@ -2606,9 +2618,14 @@ int main(int argc, char* argv[])
             write_outfile(pdf, o);
 	}
 	if (! pdf.getWarnings().empty())
+	{
+            if (! o.suppress_warnings)
             {
                 std::cerr << whoami << ": operation succeeded with warnings;"
-		      << " resulting file may have some problems" << std::endl;
+                          << " resulting file may have some problems"
+                          << std::endl;
+            }
+            // Still exit with warning code even if warnings were suppressed.
             exit(EXIT_WARNING);
 	}
     }

qpdf/qtest/qpdf.test

@@ -1528,7 +1528,7 @@ my @badfiles = ("not a PDF file", 			# 1
                 "bad dictionary key",                   # 36
 		);
 
-$n_tests += @badfiles + 3;
+$n_tests += @badfiles + 5;
 
 # Test 6 contains errors in the free table consistency, but we no
 # longer have any consistency check for this since it is not important
@@ -1552,6 +1552,14 @@ for (my $i = 1; $i <= scalar(@badfiles); ++$i)
 		 $td->NORMALIZE_NEWLINES);
 }
 
+$td->runtest("Suppress warnings",
+             {$td->COMMAND => "qpdf --no-warn bad14.pdf a.pdf"},
+             {$td->STRING => "", $td->EXIT_STATUS => 3});
+$td->runtest("Suppress warnings with --check",
+             {$td->COMMAND => "qpdf --check --no-warn bad14.pdf"},
+             {$td->FILE => "bad14-check-no-warn.out",
+                  $td->EXIT_STATUS => 3},
+             $td->NORMALIZE_NEWLINES);
 $td->runtest("C API: errors",
 	     {$td->COMMAND => "qpdf-ctest 2 bad1.pdf '' a.pdf"},
 	     {$td->FILE => "c-read-errors.out",

qpdf/qtest/qpdf/bad14-check-no-warn.out

@@ -0,0 +1,4 @@
+checking bad14.pdf
+PDF Version: 1.3
+File is not encrypted
+File is not linearized