Revert of SkStringPrintf and SkString::printf now are no longer limted by a static buffer

src/pdf/SkPDFMetadata.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkMD5.h"
 #include "SkMilestone.h"
 #include "SkPDFMetadata.h"
@@ skipping 77 matching lines @@
     //       <81b14aafa313db63dbd6f981e49f94f4> ]
     auto array = sk_make_sp<SkPDFArray>();
     static_assert(sizeof(UUID) == 16, "uuid_size");
     array->appendString(
             SkString(reinterpret_cast<const char*>(&doc), sizeof(UUID)));
     array->appendString(
             SkString(reinterpret_cast<const char*>(&instance), sizeof(UUID)));
     return array.release();
 }
 
+// Improvement on SkStringPrintf to allow for arbitrarily long output.
+// TODO: replace SkStringPrintf.
+static SkString sk_string_printf(const char* format, ...) {
+#ifdef SK_BUILD_FOR_WIN
+    va_list args;
+    va_start(args, format);
+    char buffer[1024];
+    int length = _vsnprintf_s(buffer, sizeof(buffer), _TRUNCATE, format, args);
+    va_end(args);
+    if (length >= 0 && length < (int)sizeof(buffer)) {
+        return SkString(buffer, length);
+    }
+    va_start(args, format);
+    length = _vscprintf(format, args);
+    va_end(args);
+
+    SkString string((size_t)length);
+    va_start(args, format);
+    SkDEBUGCODE(int check = ) _vsnprintf_s(string.writable_str(), length + 1,
+                                           _TRUNCATE, format, args);
+    va_end(args);
+    SkASSERT(check == length);
+    SkASSERT(string[length] == '\0');
+    return string;
+#else  // C99/C++11 standard vsnprintf
+    // TODO: When all compilers support this, remove windows-specific code.
+    va_list args;
+    va_start(args, format);
+    char buffer[1024];
+    int length = vsnprintf(buffer, sizeof(buffer), format, args);
+    va_end(args);
+    if (length < 0) {
+        return SkString();
+    }
+    if (length < (int)sizeof(buffer)) {
+        return SkString(buffer, length);
+    }
+    SkString string((size_t)length);
+    va_start(args, format);
+    SkDEBUGCODE(int check = )
+            vsnprintf(string.writable_str(), length + 1, format, args);
+    va_end(args);
+    SkASSERT(check == length);
+    SkASSERT(string[length] == '\0');
+    return string;
+#endif
+}
+
 static const SkString get(const SkTArray<SkDocument::Attribute>& info,
                           const char* key) {
     for (const auto& keyValue : info) {
         if (keyValue.fKey.equals(key)) {
             return keyValue.fValue;
         }
     }
     return SkString();
 }
 
@@ skipping 140 matching lines @@
             "</x:xmpmeta>\n"  // Note:  the standard suggests 4k of padding.
             "<?xpacket end=\"w\"?>\n";
 
     SkString creationDate;
     SkString modificationDate;
     if (fCreation) {
         SkString tmp;
         fCreation->toISO8601(&tmp);
         SkASSERT(0 == count_xml_escape_size(tmp));
         // YYYY-mm-ddTHH:MM:SS[+|-]ZZ:ZZ; no need to escape
-        creationDate = SkStringPrintf("<xmp:CreateDate>%s</xmp:CreateDate>\n",
-                                      tmp.c_str());
+        creationDate = sk_string_printf("<xmp:CreateDate>%s</xmp:CreateDate>\n",
+                                        tmp.c_str());
     }
     if (fModified) {
         SkString tmp;
         fModified->toISO8601(&tmp);
         SkASSERT(0 == count_xml_escape_size(tmp));
-        modificationDate = SkStringPrintf(
+        modificationDate = sk_string_printf(
                 "<xmp:ModifyDate>%s</xmp:ModifyDate>\n", tmp.c_str());
     }
     SkString title = escape_xml(
             get(fInfo, "Title"),
             "<dc:title><rdf:Alt><rdf:li xml:lang=\"x-default\">",
             "</rdf:li></rdf:Alt></dc:title>\n");
     SkString author = escape_xml(
             get(fInfo, "Author"), "<dc:creator><rdf:Bag><rdf:li>",
             "</rdf:li></rdf:Bag></dc:creator>\n");
     // TODO: in theory, XMP can support multiple authors.  Split on a delimiter?
     SkString subject = escape_xml(
             get(fInfo, "Subject"),
             "<dc:description><rdf:Alt><rdf:li xml:lang=\"x-default\">",
             "</rdf:li></rdf:Alt></dc:description>\n");
     SkString keywords1 = escape_xml(
             get(fInfo, "Keywords"), "<dc:subject><rdf:Bag><rdf:li>",
             "</rdf:li></rdf:Bag></dc:subject>\n");
     SkString keywords2 = escape_xml(
             get(fInfo, "Keywords"), "<pdf:Keywords>",
             "</pdf:Keywords>\n");
 
     // TODO: in theory, keywords can be a list too.
     SkString creator = escape_xml(get(fInfo, "Creator"), "<xmp:CreatorTool>",
                                   "</xmp:CreatorTool>\n");
     SkString documentID = uuid_to_string(doc);  // no need to escape
     SkASSERT(0 == count_xml_escape_size(documentID));
     SkString instanceID = uuid_to_string(instance);
     SkASSERT(0 == count_xml_escape_size(instanceID));
-    return new PDFXMLObject(SkStringPrintf(
+    return new PDFXMLObject(sk_string_printf(
             templateString, modificationDate.c_str(), creationDate.c_str(),
             creator.c_str(), title.c_str(),
             subject.c_str(), author.c_str(), keywords1.c_str(),
             documentID.c_str(), instanceID.c_str(), keywords2.c_str()));
 }
 
 #undef SKPDF_STRING
 #undef SKPDF_STRING_IMPL