Pdfium Patch to restore PS Path

core/fxcodec/codec/fx_codec.cpp

Index: core/fxcodec/codec/fx_codec.cpp
diff --git a/core/fxcodec/codec/fx_codec.cpp b/core/fxcodec/codec/fx_codec.cpp
index aa2ecef34576ce49c4ed8da5b1f48cba07ee7393..bf9a4d9dbdec8b19b44ef15510331ff9408020c3 100644
--- a/core/fxcodec/codec/fx_codec.cpp
+++ b/core/fxcodec/codec/fx_codec.cpp
@@ -97,6 +97,158 @@ uint8_t* CCodec_ScanlineDecoder::ReadNextLine() {
   return v_GetNextLine();
 }
 
+bool CCodec_BasicModule::RunLengthEncode(const uint8_t* src_buf,
+                                         uint32_t src_size,
+                                         uint8_t*& dest_buf,
+                                         uint32_t& dest_size) {
+  // Handle edge cases
+  if (src_size == 0)
+    return false;
+  if (src_size == 1) {
+    dest_buf = FX_Alloc(uint8_t, 3);
+    dest_buf[0] = 0;
+    dest_buf[1] = src_buf[0];
+    dest_buf[2] = 128;
+    return true;
+  }
+
+  uint32_t est_size = src_size * 2;
+  dest_buf = FX_Alloc(uint8_t, est_size);
+
+  // Set up pointers.
+  uint8_t* out = dest_buf;
+  uint32_t run_start = 0;
+  uint32_t run_end = 1;
+  uint8_t x = src_buf[run_start];
+  uint8_t y = src_buf[run_end];
+  while (run_end < src_size) {
+    uint32_t max_len = run_start + 128 < src_size ? 128 : src_size - run_start;
+    while (x == y && ((run_end - run_start) < max_len - 1))
+      y = src_buf[++run_end];
+    // Reached end with matched run. Update variables to expected values.
+    if (x == y) {
+      run_end++;
+      if (run_end < src_size)
+        y = src_buf[run_end];
+    }
+    if (run_end - run_start > 1) {  // Matched run
+      out[0] = 257 - (run_end - run_start);
+      out[1] = x;
+      x = y;
+      run_start = run_end;
+      run_end++;
+      if (run_end < src_size)
+        y = src_buf[run_end];
+      out += 2;
+      continue;
+    }
+    // Mismatched run
+    while (x != y && run_end <= run_start + max_len) {
+      out[(run_end - run_start)] = x;
+      x = y;
+      run_end++;
+      if (run_end == src_size) {
+        if (run_end <= run_start + max_len) {
+          out[(run_end - run_start)] = x;
+          run_end++;
+        }
+        break;
+      }
+      y = src_buf[run_end];
+    }
+    out[0] = run_end - run_start - 2;
+    out += run_end - run_start;
+    run_start = run_end - 1;
+  }
+  if (run_start < src_size) {
+    out[0] = 0;
+    out[1] = x;
+    out += 2;
+  }
+  *out = 128;
+  dest_size = out + 1 - dest_buf;
+  return true;
+}
+
+namespace A85Encode {
+static const uint64_t a[4] = {256 * 256 * 256, 256 * 256, 256, 1};
+static const uint64_t b[5] = {85 * 85 * 85 * 85, 85 * 85 * 85, 85 * 85, 85, 1};
+}
+
+bool CCodec_BasicModule::A85Encode(const uint8_t* src_buf,
+                                   uint32_t src_size,
+                                   uint8_t*& dest_buf,
+                                   uint32_t& dest_size) {
+  // Handle edge cases
+  if (src_size == 0) {
+    dest_size = 0;
+    return false;
+  }
+
+  uint32_t est_size = 5 * (src_size / 4 + 1) + src_size / 30 + 1;
+  dest_buf = FX_Alloc(uint8_t, est_size);
+
+  // Set up pointers.
+  uint8_t* out = dest_buf;
+  uint32_t pos = 0;
+  uint32_t line_length = 0;
+  while (src_size >= 4 && pos < src_size - 3) {
+    uint64_t val = (uint64_t)(src_buf[pos]) * A85Encode::a[0] +
+                   (uint64_t)(src_buf[pos + 1]) * A85Encode::a[1] +
+                   (uint64_t)(src_buf[pos + 2]) * A85Encode::a[2] +
+                   (uint64_t)(src_buf[pos + 3]);
+    pos += 4;
+    if (val == 0) {  // All zero special case
+      *out = 'z';
+      out++;
+      line_length++;
+    } else {
+      uint64_t c1 = val / A85Encode::b[0];
+      val -= c1 * A85Encode::b[0];
+      out[0] = (uint8_t)c1 + 33;
+      uint64_t c2 = val / A85Encode::b[1];
+      val -= c2 * A85Encode::b[1];
+      out[1] = (uint8_t)c2 + 33;
+      uint64_t c3 = val / A85Encode::b[2];
+      val -= c3 * A85Encode::b[2];
+      out[2] = (uint8_t)c3 + 33;
+      uint64_t c4 = val / A85Encode::b[3];
+      val -= c4 * A85Encode::b[3];
+      out[3] = (uint8_t)c4 + 33;
+      out[4] = (uint8_t)val + 33;
+      out += 5;
+      line_length += 5;
+    }
+    if (line_length >= 75) {
+      *out = '\r';
+      *++out = '\n';
+      out++;
+      line_length = 0;
+    }
+  }
+  if (pos < src_size) {  // Leftover bytes
+    uint64_t val = 0;
+    uint32_t count = 0;
+    while (pos < src_size) {
+      val += (uint64_t)(src_buf[pos]) * A85Encode::a[count];
+      count++;
+      pos++;
+    }
+    for (uint32_t i = 0; i < count + 1; i++) {
+      uint64_t c = val / A85Encode::b[i];
+      val -= c * A85Encode::b[i];
+      out[i] = (uint8_t)c + 33;
+    }
+    out += count + 1;
+  }
+
+  out[0] = '~';
+  out[1] = '>';
+  out += 2;
+  dest_size = out - dest_buf;
+  return true;
+}
+
 #ifdef PDF_ENABLE_XFA
 CFX_DIBAttribute::CFX_DIBAttribute()
     : m_nXDPI(-1),