clang-format: [JS] don't break comments before any '{'

Summary:
Previously, clang-format would avoid breaking before the first `{`
found, but then happily break before subsequent '{'s on the line. This
change fixes that by looking for the first location that has no opening
curly, if any.

This fixes the original commit by correcting the loop condition.

This reverts commit 66dc646e09b795b943668179c33d09da71a3b6bc.

Reviewers: krasimir

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D50249

llvm-svn: 338890
diff --git a/clang/lib/Format/BreakableToken.cpp b/clang/lib/Format/BreakableToken.cpp
index 300e3f8..e6ce01b 100644
--- a/clang/lib/Format/BreakableToken.cpp
+++ b/clang/lib/Format/BreakableToken.cpp
@@ -90,19 +90,21 @@
 
   StringRef::size_type SpaceOffset = Text.find_last_of(Blanks, MaxSplitBytes);
 
-  // Do not split before a number followed by a dot: this would be interpreted
-  // as a numbered list, which would prevent re-flowing in subsequent passes.
   static auto *const kNumberedListRegexp = new llvm::Regex("^[1-9][0-9]?\\.");
-  if (SpaceOffset != StringRef::npos &&
-      kNumberedListRegexp->match(Text.substr(SpaceOffset).ltrim(Blanks)))
-    SpaceOffset = Text.find_last_of(Blanks, SpaceOffset);
-  // In JavaScript, some @tags can be followed by {, and machinery that parses
-  // these comments will fail to understand the comment if followed by a line
-  // break. So avoid ever breaking before a {.
-  if (Style.Language == FormatStyle::LK_JavaScript &&
-      SpaceOffset != StringRef::npos && SpaceOffset + 1 < Text.size() &&
-      Text[SpaceOffset + 1] == '{')
-    SpaceOffset = Text.find_last_of(Blanks, SpaceOffset);
+  while (SpaceOffset != StringRef::npos) {
+    // Do not split before a number followed by a dot: this would be interpreted
+    // as a numbered list, which would prevent re-flowing in subsequent passes.
+    if (kNumberedListRegexp->match(Text.substr(SpaceOffset).ltrim(Blanks)))
+      SpaceOffset = Text.find_last_of(Blanks, SpaceOffset);
+    // In JavaScript, some @tags can be followed by {, and machinery that parses
+    // these comments will fail to understand the comment if followed by a line
+    // break. So avoid ever breaking before a {.
+    else if (Style.Language == FormatStyle::LK_JavaScript &&
+             SpaceOffset + 1 < Text.size() && Text[SpaceOffset + 1] == '{')
+      SpaceOffset = Text.find_last_of(Blanks, SpaceOffset);
+    else
+      break;
+  }
 
   if (SpaceOffset == StringRef::npos ||
       // Don't break at leading whitespace.