[sfntdiff] Support diff'ing different font formats

Fixes #626

c/sfntdiff/source/Dfile.c

@@ -5,16 +5,17 @@
 /*
  * Machine independant file operations. The ANSI standard buffered i/o library
  * can't be used here because the Macintosh version doesn't support resource
- * reading. 
+ * reading.
  *
  * This code assumes that 32 bits is large enough to hold a file offset. This
  * seems a safe assumtion since other code would break long before
- * fonts/resource files reached this size. 
+ * fonts/resource files reached this size.
  */
 
 #include <stdio.h>
 #include <stdarg.h>
 #include <string.h>
+#include <stdbool.h>
 
 #include "Dglobal.h"
 #include "Dfile.h"
@@ -250,3 +251,23 @@ Card32 fileSniff(Card8 which) {
     fileSeekAbsNotBuffered(which, 0);
     return value;
 }
+
+bool isSupportedFontFormat(Card32 value, Byte8 *fname) {
+    switch (value) {
+        case bits_:
+        case typ1_:
+        case true_:
+        case OTTO_:
+        case VERSION(1, 0):
+            return true;
+            break;
+        case 256:
+        case ttcf_:
+            warning("unsupported file [%s] (ignored)\n", fname);
+            return false;
+            break;
+        default:
+            warning("unsupported/bad file [%s] (ignored)\n", fname);
+            return false;
+    }
+}

c/sfntdiff/source/Dfile.h

@@ -6,6 +6,7 @@
  * File input support.
  */
 
+#include <stdbool.h>
 #ifndef FILE_H
 #define FILE_H
 
@@ -20,6 +21,7 @@ extern void fileReadBytes(Card8 which, Int32 count, Card8 *buf);
 extern void fileReadObject(Card8 which, IntX size, ...);
 extern Byte8 *fileName(Card8 which);
 extern Card32 fileSniff(Card8 which);
+extern bool isSupportedFontFormat(Card32 value, Byte8 *fname);
 
 /* Convienience macros */
 #define TELL(which)           fileTell((which))

c/sfntdiff/source/Dmain.c

@@ -10,8 +10,9 @@
 #include "Dsys.h"
 #include <ctype.h>
 #include <string.h>
+#include <stdbool.h>
 
-Byte8 *version = "2.21217"; /* Program version */
+Byte8 *version = "3.0.0"; /* Program version */
 
 static char *sourcepath = "";
 #include "setjmp.h"
@@ -100,7 +101,7 @@ IntN main(IntN argc, Byte8 *argv[]) {
 
     volatile IntX i = 0;
     IntN argi;
-    Card32 value, value2;
+    bool supported, supported2;
     Byte8 *filename1;
     Byte8 *filename2;
     IntN name1isDir, name2isDir;
@@ -151,34 +152,16 @@ IntN main(IntN argc, Byte8 *argv[]) {
         }
 
         /* See if we can recognize the file type */
-        value = fileSniff(1);
-        value2 = fileSniff(2);
-        if (value != value2) {
+        supported = isSupportedFontFormat(fileSniff(1), filename1);
+        supported2 = isSupportedFontFormat(fileSniff(2), filename2);
+
+        if (!supported || !supported2) {
             fileClose(1);
             fileClose(2);
-            fatal("file1 [%s] is not the same type as file2 [%s]\n", filename1, filename2);
+            quit(1);
         }
 
-        switch (value) {
-            case bits_:
-            case typ1_:
-            case true_:
-            case OTTO_:
-            case VERSION(1, 0):
-                sfntRead(0, -1, 0, -1); /* Read plain sfnt file */
-                break;
-            case ttcf_:
-                warning("unsupported file [%s] (ignored)\n", filename1);
-                fileClose(1);
-                fileClose(2);
-                quit(1);
-                break;
-            default:
-                warning("unsupported/bad file [%s] (ignored)\n", filename1);
-                fileClose(1);
-                fileClose(2);
-                quit(1);
-        }
+        sfntRead(0, -1, 0, -1); /* Read plain sfnt file */
         sfntDump();
         sfntFree();
         fileClose(1);
@@ -211,35 +194,16 @@ IntN main(IntN argc, Byte8 *argv[]) {
             }
 
             /* See if we can recognize the file type */
-            value = fileSniff(1);
-            value2 = fileSniff(2);
-            if (value != value2) {
+            supported = isSupportedFontFormat(fileSniff(1), fil1);
+            supported2 = isSupportedFontFormat(fileSniff(2), fil2);
+
+            if (!supported || !supported2) {
                 fileClose(1);
                 fileClose(2);
-                fatal("file1 [%s] is not the same type as file2 [%s]\n", fil1, fil2);
+                continue;
             }
 
-            switch (value) {
-                case bits_:
-                case typ1_:
-                case true_:
-                case OTTO_:
-                case VERSION(1, 0):
-                    sfntRead(0, -1, 0, -1); /* Read plain sfnt file */
-                    break;
-                case 256:
-                case ttcf_:
-                    warning("unsupported file [%s] (ignored)\n", fil1);
-                    fileClose(1);
-                    fileClose(2);
-                    quit(1);
-                    break;
-                default:
-                    warning("unsupported/bad file [%s] (ignored)\n", fil1);
-                    fileClose(1);
-                    fileClose(2);
-                    continue;
-            }
+            sfntRead(0, -1, 0, -1); /* Read plain sfnt file */
             sfntDump();
             sfntFree();
             fileClose(1);
@@ -269,35 +233,16 @@ IntN main(IntN argc, Byte8 *argv[]) {
         }
 
         /* See if we can recognize the file type */
-        value = fileSniff(1);
-        value2 = fileSniff(2);
-        if (value != value2) {
+        supported = isSupportedFontFormat(fileSniff(1), filename1);
+        supported2 = isSupportedFontFormat(fileSniff(2), fil2);
+
+        if (!supported || !supported2) {
             fileClose(1);
             fileClose(2);
-            fatal("file1 [%s] is not the same type as file2 [%s]\n", filename1, fil2);
+            quit(1);
         }
 
-        switch (value) {
-            case bits_:
-            case typ1_:
-            case true_:
-            case OTTO_:
-            case VERSION(1, 0):
-                sfntRead(0, -1, 0, -1); /* Read plain sfnt file */
-                break;
-            case 256:
-            case ttcf_:
-                warning("unsupported file [%s] (ignored)\n", filename1);
-                fileClose(1);
-                fileClose(2);
-                quit(1);
-                break;
-            default:
-                warning("unsupported/bad file [%s] (ignored)\n", filename1);
-                fileClose(1);
-                fileClose(2);
-                quit(1);
-        }
+        sfntRead(0, -1, 0, -1); /* Read plain sfnt file */
         sfntDump();
         sfntFree();
         fileClose(1);

tests/sfntdiff_data/expected_output/bug626.txt

@@ -0,0 +1,8 @@
+Thu Mar 14 02:59:39 2019
+sfntdiff (2.21217) (-d 0)  files:
+< SourceSerifPro-It.otf
+> SourceSerifPro-It.ttf
+'sfnt' differs.
+'head' differs.
+'maxp' differs.
+'post' differs.

tests/sfntdiff_test.py

@@ -8,6 +8,7 @@
 from test_utils import get_expected_path
 
 TOOL = 'sfntdiff'
+CMD = ['-t', TOOL]
 
 
 # -----
@@ -41,7 +42,23 @@ def test_exit_unknown_option(arg):
 def test_diff(args, txt_filename):
     if args:
         args.insert(0, '-o')
-    actual_path = runner(
-        ['-t', TOOL, '-s', '-f', 'regular.otf', 'bold.otf'] + args)
+    actual_path = runner(CMD + ['-s', '-f', 'regular.otf', 'bold.otf'] + args)
     expected_path = get_expected_path(txt_filename)
     assert differ([expected_path, actual_path, '-l', '1-4'])
+
+
+def test_diff_otf_vs_ttf_bug626():
+    actual_path = runner(CMD + ['-s', '-f', 'SourceSerifPro-It.otf',
+                                            'SourceSerifPro-It.ttf'])
+    expected_path = get_expected_path('bug626.txt')
+    assert differ([expected_path, actual_path, '-l', '1-4'])
+
+
+def test_not_font_files():
+    stderr_path = runner(CMD + ['-s', '-e', '-f', 'not_a_font_1.otf',
+                                                  'not_a_font_2.otf'])
+    with open(stderr_path, 'rb') as f:
+        output = f.read()
+    assert b'[WARNING]: unsupported/bad file' in output
+    assert b'not_a_font_1.otf] (ignored)' in output
+    assert b'not_a_font_2.otf] (ignored)' in output