Fix #2370: the equations are slightly misaligned in LaTeX

CHANGES

@@ -4,6 +4,8 @@ Release 1.4.2 (in development)
 Bugs fixed
 ----------
 
+* #2370: the equations are slightly misaligned in LaTeX writer
+
 
 Release 1.4.1 (released Apr 12, 2016)
 =====================================

sphinx/ext/mathbase.py

@@ -31,10 +31,10 @@ class eqref(nodes.Inline, nodes.TextElement):
 def wrap_displaymath(math, label, numbering):
     parts = math.split('\n\n')
     ret = []
-    for i, part in enumerate(parts):
+    for part in parts:
         if not part.strip():
             continue
-        ret.append(r'\begin{split}%s\end{split}' % part)
+        ret.append('\\!\\begin{split}%s\\end{split}\\\\\n' % part)
     if not ret:
         return ''
     if label is not None or numbering:
@@ -45,8 +45,7 @@ def wrap_displaymath(math, label, numbering):
     else:
         env_begin = r'\begin{align*}'
         env_end = r'\end{align*}'
-    return ('%s\\begin{aligned}\n%s\\end{aligned}%s') % (
-        env_begin, '\\\\\n'.join(ret), env_end)
+    return '%s\\begin{aligned}\n%s\\end{aligned}%s' % (env_begin, ''.join(ret), env_end)
 
 
 def math_role(role, rawtext, text, lineno, inliner, options={}, content=[]):

tests/test_ext_math.py

@@ -71,3 +71,22 @@ def test_math_number_all_latex(app, status, warning):
     app.builder.build_all()
 
     content = (app.outdir / 'test.tex').text()
+    print content
+    macro = (r'\\begin{align\*}\\begin{aligned}\s*'
+             r'\\!\\begin{split}a\^2\+b\^2=c\^2\\end{split}\\\\\s*'
+             r'\\end{aligned}\\end{align\*}')
+    assert re.search(macro, content, re.S)
+
+    macro = r'Inline \\\(E=mc\^2\\\)'
+    assert re.search(macro, content, re.S)
+
+    macro = (r'\\begin{align\*}\\begin{aligned}\s*'
+             r'\\!\\begin{split}e\^{i\\pi}\+1=0\\end{split}\\\\\s+'
+             r'\\end{aligned}\\end{align\*}')
+    assert re.search(macro, content, re.S)
+
+    macro = (r'\\begin{align\*}\\begin{aligned}\s*'
+             r'\\!\\begin{split}S &= \\pi r\^2\\end{split}\\\\\s*'
+             r'\\!\\begin{split}V &= \\frac\{4}\{3} \\pi r\^3\\end{split}\\\\\s*'
+             r'\\end{aligned}\\end{align\*}')
+    assert re.search(macro, content, re.S)