Improved word break for BiDi pseudolocalizer.

Characted sequences \n and \t are now treated as word separators
by BiDi pseudolocalizer. This solves issues when text rendering
engine breaks a line in the middle of a text chunk marked with
RLM+RLO and PDF+RLM sequences.

Bug:34064580
Change-Id: I52e6018785fae25479fa167440f24c534b0e3253
Fixes:34064580
Test: make aapt2_tests
Test: Run aapt2_tests binary

4 files changed, 31 insertions, 2 deletions

diff --git a/tools/aapt/pseudolocalize.cpp b/tools/aapt/pseudolocalize.cpp
index c7fee2c19342..5c47e0fa8a16 100644
--- a/tools/aapt/pseudolocalize.cpp
+++ b/tools/aapt/pseudolocalize.cpp
@@ -360,9 +360,15 @@ String16 PseudoMethodBidi::text(const String16& source)
     String16 result;
     bool lastspace = true;
     bool space = true;
+    bool escape = false;
+    const char16_t ESCAPE_CHAR = '\\';
     for (size_t i=0; i<source.size(); i++) {
         char16_t c = s[i];
-        space = is_space(c);
+        if (!escape && c == ESCAPE_CHAR) {
+          escape = true;
+          continue;
+        }
+        space = (!escape && is_space(c)) || (escape && (c == 'n' || c == 't'));
         if (lastspace && !space) {
           // Word start
           result += k_rlm + k_rlo;
@@ -371,6 +377,10 @@ String16 PseudoMethodBidi::text(const String16& source)
           result += k_pdf + k_rlm;
         }
         lastspace = space;
+        if (escape) {
+          result.append(&ESCAPE_CHAR, 1);
+          escape=false;
+        }
         result.append(&c, 1);
     }
     if (!lastspace) {
diff --git a/tools/aapt/tests/Pseudolocales_test.cpp b/tools/aapt/tests/Pseudolocales_test.cpp
index 4670e9fd53ea..a6aed3abd7cf 100644
--- a/tools/aapt/tests/Pseudolocales_test.cpp
+++ b/tools/aapt/tests/Pseudolocales_test.cpp
@@ -87,6 +87,10 @@ TEST(Pseudolocales, PlaintextBidi) {
                 "\xe2\x80\x8f\xE2\x80\xaehello\xE2\x80\xac\xe2\x80\x8f\n" \
                 "  \xe2\x80\x8f\xE2\x80\xaeworld\xE2\x80\xac\xe2\x80\x8f\n",
                 PSEUDO_BIDI);
+  simple_helper("hello\\nworld\\n",
+                "\xe2\x80\x8f\xE2\x80\xaehello\xE2\x80\xac\xe2\x80\x8f\\n"
+                "\xe2\x80\x8f\xE2\x80\xaeworld\xE2\x80\xac\xe2\x80\x8f\\n",
+                PSEUDO_BIDI);
 }
 
 TEST(Pseudolocales, SimpleICU) {
diff --git a/tools/aapt2/compile/Pseudolocalizer.cpp b/tools/aapt2/compile/Pseudolocalizer.cpp
index 15a3d8c289e2..3a515fad3202 100644
--- a/tools/aapt2/compile/Pseudolocalizer.cpp
+++ b/tools/aapt2/compile/Pseudolocalizer.cpp
@@ -445,9 +445,15 @@ std::string PseudoMethodBidi::Text(const StringPiece& source) {
   std::string result;
   bool lastspace = true;
   bool space = true;
+  bool escape = false;
+  const char ESCAPE_CHAR = '\\';
   for (size_t i = 0; i < source.size(); i++) {
     char c = s[i];
-    space = isspace(c);
+    if (!escape && c == ESCAPE_CHAR) {
+      escape = true;
+      continue;
+    }
+    space = (!escape && isspace(c)) || (escape && (c == 'n' || c == 't'));
     if (lastspace && !space) {
       // Word start
       result += kRlm + kRlo;
@@ -456,6 +462,10 @@ std::string PseudoMethodBidi::Text(const StringPiece& source) {
       result += kPdf + kRlm;
     }
     lastspace = space;
+    if (escape) {
+      result.append(&ESCAPE_CHAR, 1);
+      escape=false;
+    }
     result.append(&c, 1);
   }
   if (!lastspace) {
diff --git a/tools/aapt2/compile/Pseudolocalizer_test.cpp b/tools/aapt2/compile/Pseudolocalizer_test.cpp
index d3b7b02d1abb..65d2472ef2a9 100644
--- a/tools/aapt2/compile/Pseudolocalizer_test.cpp
+++ b/tools/aapt2/compile/Pseudolocalizer_test.cpp
@@ -97,6 +97,11 @@ TEST(PseudolocalizerTest, PlaintextBidi) {
       "\xe2\x80\x8f\xE2\x80\xaehello\xE2\x80\xac\xe2\x80\x8f\n"
       "  \xe2\x80\x8f\xE2\x80\xaeworld\xE2\x80\xac\xe2\x80\x8f\n",
       Pseudolocalizer::Method::kBidi));
+  EXPECT_TRUE(
+      SimpleHelper("hello\\nworld\\n",
+                   "\xe2\x80\x8f\xE2\x80\xaehello\xE2\x80\xac\xe2\x80\x8f\\n"
+                   "\xe2\x80\x8f\xE2\x80\xaeworld\xE2\x80\xac\xe2\x80\x8f\\n",
+                   Pseudolocalizer::Method::kBidi));
 }
 
 TEST(PseudolocalizerTest, SimpleICU) {